The Importance of Conserving
the Wolves of Isle Royale National Park
June 28, 2013
John A. Vucetich,
School of Forest Resources and Environmental Science, Michigan Technological University, Houghton, MI 49931 USA, javuceti@mtu.edu
Rolf O. Peterson,
School of Forest Resources and Environmental Science, Michigan Technological University, Houghton, MI 49931 USA, ropeters@mtu.edu
Michael P. Nelson,
Department of Forest Ecosystems and Society, Oregon State University, Corvallis, OR 97331 USA, mpnelson@oregonstate.edu
DRAFT – DO NOT DISTRIBUTE
We are grateful to Daniel Botkin, Rich Fredrickson, Phil Hedrick, Mike Phillips, and Lucas Westcott for dialogue that
inspired the development of various elements of this document. The views expressed here do not necessarily represent
their views or the views of our employers.
We express special thanks The George Wright Forum for allowing us to reprint excerpts of papers that had originally
been published there (http://www.georgewright.org/forum.html).
Suggestion citation: Vucetich, JA., R. O. Peterson, M. P. Nelson. 2013. The importance of conserving
the wolves of Isle Royale National Park. Michigan Technological University., 50 pages.
1
ANNOTATED CONTENTS
Preface……………..…………………………………………………....….………………………3
Executive Summary……...………………………………………..........…………….…………4
1. The history of wolves and moose on Isle Royale……..…..…....……………..…………6
2. As long as there are moose, there should be wolves…………..…………………………14
The analysis presented here considers some of key environmental values, such as ecosystem health and wilderness character, that would be affected by deciding how to treat the wolves of Isle Royale. That analysis indicates that wolves should be present on Isle Royale so long as moose inhabit the island and so long as ecosystem health is a priority for the National Park Service. As such, not intervening, even in the event of extinction, would be antithetical to the NPS mission.
3. Conservation is preferable to restoration………………………………………..………..21 The analysis presented here explains why preserving predation through genetic rescue is preferable to attempting to restore predation, if the population should go extinct. The precautionary principle plays an important role in arriving at this conclusion.
4. Climate Change and moose. ………………………………………………………..……..27 The analysis presented here addresses the concern that detrimental effects of climate change on moose provides reason for allowing wolves to go extinct. The analysis indicates how that concern is misplaced.
5. Isle Royale’s dynamic fauna.……………………………………………………..…...…..32 The analysis presented here addresses the concern that wolves should be allowed to go extinct because humans may have played a role in wolves and moose colonizing Isle Royale or because extinction on a small island is a natural process that should be allowed. The analysis indicates how these concerns are misplaced.
6. Pandora’s box? ………………………………………….…………………………......…..35 The analysis presented here addresses the concern that conserving Isle Royale wolves would represent a radical departure from NPS’s strong, effective and time-­‐tested tradition of giving deference to non-­‐intervention as a method for fulTilling its mission to preserve ecosystem health. There is also concern that conserving Isle Royale wolves would open Pandora’s Box, justifying a myriad of misguided attempts to resist the inevitable affects of human-­‐caused global change. The analysis indicates how these concerns are misplaced.
Literature Cited..........................................................................................39
Appendices ...............................................................................................45
2
PREFACE
In 2012, the director of the National Park Service commissioned a report, Revisiting Leopold: Resource Stewardship in the National Parks. That report presents a management philosophy that confronts the unprecedented level of human-­‐caused global changes – changes such as climate destabilization, widespread carnivore extinctions, spread of exotic species and novel diseases, altered biogeochemical cycles, and rampant habitat destruction. While the analysis of policy is routinely the purview of government employees or their representatives, one conclusion of that report is that: “the public must be made aware of the challenges facing the National Park System and urged and empowered to take action to preserve and protect these resources as part of their enduring responsibility as citizens.” The analysis presented in this document is our accepting of that call to responsibility. The analysis is also constructed with special reference to the mission of the National Park Service, which is to “preserve unimpaired the natural and cultural resources and values of the national park system for the enjoyment, education, and inspiration of this and future generations.” We hope this document is found to be constructive and useful.
3
EXECUTIVE SUMMARY
Isle Royale National Park is a remote wilderness island in Lake Superior where wolves and moose h a v e b e e n e n t a n g l e d i n a d y n a m i c interconnectedness and dramatic expression of life and death since wolves Tirst arrived there in the late 1940s by crossing an ice bridge from Canada. But the wolf population is small and decades of inbreeding have taken their toll. Human-­‐
introduced disease is also likely to have exacerbated the wolves’ situation. Ice bridges that once would have allowed mainland wolves to infuse the wolf population with new genes form far less frequently because of climate warming. Now Isle Royale wolves face considerable risk of extinction and humans have likely contributed signiTicantly to this impairment. The impaired condition of Isle Royale wolves provides occasion to evaluate what kind of management response is appropriate given the wolf population’s condition. There seem to be three options: (i) conserve Isle Royale wolves with an action known as genetic rescue by bringing some wolves to the island to mitigate inbreeding; (ii) restore predation by reintroducing wolves to Isle Royale, if and when they go extinct; or (iii) do not intervene, even if wolves go extinct. The mission of our National Park Service is to preserve outstanding examples of ecosystem integrity for the education and enjoyment of this and future generations. In this regard, Isle Royale is an exceedingly rare and outstanding kind of ecosystem on the planet because humans hunt neither its wolves nor moose, nor log its forests. Isle Royale is critically unique because each year many thousands of citizens experience and learn of that beauty. Isle Royale wolves are also the subject of the longest continuous study of any predator-­‐prey system in the world. That research is some of the best-­‐known research in the NPS system. This is germane because the NPS also has a mandate to 4
facilitate the development of scientiTic knowledge about the natural world. Non-­‐intervention is an inappropriate option because the presence of wolf predation is a critical component of health for ecosystems inhabited by ungulates. In general, top predators are important because exhaustive scientiTic evidence has demonstrated their pervasive inTluences on ecosystems – inTluences that are not substituted for by hunting or culling large ungulates. Nevertheless, humans have driven to extinction a staggering number of predator populations from many different kinds of ecosystems across the planet. The harm in that loss is well reTlected by the conservation philosophy of Aldo Leopold, aspects of which are aptly captured by his oft-­‐
repeated aphorisms, “To keep every cog and wheel is the Tirst precaution of intelligent tinkering” and “A thing is right when it tends to preserve the integrity, stability, and beauty of the biotic community. It is wrong when it tends otherwise”. For all of these reasons, there should be wolves on Isle Royale as long as there are moose. Moreover, the precautionary principle indicates that conserving Isle Royale wolves through genetic rescue is considerably more appropriate than attempting restoration should they go extinct. One problem with attempting restoration is that it will almost certainly be associated with a signiTicant discontinuity in predation processes. Even a brief discontinuity in predation would likely result in long-­‐lasting detrimental impacts of the ecological integrity of Isle Royale’s forests. For these reasons, genetic rescue seems the most appropriate response. Genetic rescue is the easiest, quickest, and most reliable means of preserving the ecosystem integrity of Isle Royale. In general, if a natural process is valued, it seems straightforward to conserve it, rather than let it be lost with the expectation that it can later be restored. Some has said that the detrimental affects of climate change on the Isle Royale moose population is a reason not to conserve predation on Isle Royale. While moose are certainly affected by climate, existing evidence does not support the claim that climate change has impaired Isle Royale moose. It would be boldly unwise, with far reaching implications, to suggest that a top predator should not be conserved because climate change might threaten the viability of their prey at some indeTinite time in the future.
enough honor to anthropogenic losses like those occurring with Isle Royale wolves. Because of the what we have done to the world, Isle Royale has become a globally unique ecosystem for simultaneously being inhabited by a top predator; for being intact in the sense that humans hunt neither wolves nor moose, nor log its forests; and for being accessible for citizens to witness. Honoring predation overrides the interest to honor extinction. Some have suggested that Isle Royale’s wolves should be allowed to go extinct because humans may have played a role in wolves and moose colonizing Isle Royale. One reason for this concern being misplaced is that the evidence for those claims about colonization is wildly speculative, at best.
Some are concerned that conserving Isle Royale wolves would open a Pandora’s Box, justifying a myriad of misguided attempts to resist the inevitable affects of human-­‐caused global change. A related concern is that conserving Isle Royale wolves would represent a radical departure from the NPS’s strong, effective and time-­‐tested tradition of giving deference to non-­‐intervention as a method for fulTilling its mission to preserve ecosystem health. Others have suggested that Isle Royale’s wolves should be allowed to go extinct because extinction is a natural process, especially on small, remote islands. Preserving (or restoring) wolf predation would interfere with that natural process. This perspective is misplace insomuch as evidence suggests humans played an important role in the impairment and potential extinction of Isle Royale wolves. Nevertheless, suppose that Isle Royale would, in some sense, be more “natural” if wolves were allowed to go extinct. Honoring extinction as a natural process might be appropriate if we lived in a world where intact ecosystems, complete with top predators, were common. We do not live in such a world. We live in a world that has summarily dishonored top-­‐predators and their contributions to ecosystem health. Top predators have been impaired or driven to extinction across most of the planet’s land-­‐ and sea-­‐scapes. We have g i v e n m o r e t h a n In the past, the most reliable means of preserving the integrity of ecosystems required refraining from intervening with ecosystems, or at most intervening only to mitigate what humans had altered. Today, we live in a world where every portion of the earth has been altered by one or several human inTluences – climate change, exotic species, introduced diseases, widespread loss of predators, and so on. From today forward, there w i l l b e i n c r e a s i n g i n s t a n c e s w h e r e t h e preservation of an ecosystem’s integrity will require human assistance. Wisdom will always be required for knowing w h e n t o a s s i s t . Intervening in such cases is not contrary to the mission of the N a t i o n a l P a r k Service, it is essential for fulTilling it. The wolf population of Isle Royale seems to be one of these cases.
5
1. THE HISTORY OF WOLVES AND MOOSE
ON ISLE ROYALE1 Isle Royale National Park is located in the northwest portion of Lake Superior, approximately 24 km from the Canadian mainland. Moose arrived on Isle Royale, apparently for the Tirst time, early in the 20th century (Clark 1995). Moose most likely swam to Isle Royale (Mech 1966). However, some staff members of Isle Royale National Park (IRNP) and long-­‐time residents of Isle Royale believe moose were brought to Isle Royale by humans (see also Scarpino 2011). There is no direct evidence to indicate how moose arrived.
Moose lived on Isle Royale for about Tive decades in the absence of wolves. Without predation, moose increased to a very high level, perhaps 3,000 or more (>6 moose/km2) by the late 1920s (Murie 1934). During this population increase, moose browsing dramatically impacted Isle Royale’s forest vegetation (Murie 1934). The moose population crashed in 1934 due to an acute lack of food, increased again, and then died back once more in the 1940s (Krefting 1974). Signs of overbrowsing were still apparent in the early 1960s (Mech 1996). I s l e R o y a l e m o o s e w e r e s e e n a s overabundant during the 1920s and 1940s, and that concern was a primary wildlife management issue for the National Park Service in the late 1940s (Allen 1979). The impact of moose browsing during the Tirst half of the 20th century was dramatic enough to motivate Adolph Murie (1934) to urge that moose be culled or removed, or that large carnivores be introduced. A second important argument for introducing wolves to Isle Royale was to provide the only sanctuary from human exploitation for wolves in the central part of North America (unpublished correspondence, Michigan Technological University archives). Aldo Leopold and Sigurd Olson also supported introducing wolves to Isle Royale in the 1940s (unpublished correspondence, University of Wisconsin archives). Durward Allen (US Fish and Wildlife Service) and Victor Calahane (National Park Service) discussed how wolves might be introduced (Allen 1979). These leaders were not only advocating on behalf of Isle Royale’s wilderness character, they were also among the intellectual forefathers of our modern concept of wilderness, including the Wilderness Act of 1964. Lee Smits, a Detroit newspaper editor, strongly advocated wolf reintroduction a n d l e d a p r i v a t e e f f o r t ( i n collaboration with the NPS) that in 1952 resulted in the release of four captive-­‐raised wolves to Isle Royale. These plans were carried out even though it was known that wolves had already colonized Isle Royale on their own, most likely by crossing an ice bridge sometime between 1948 and 1950 (unpublished correspondence, Figure 1. The loca0on of Isle Royale Na0onal Park in Lake Superior, Michigan Technological University North America.
1
This section is adapted from Vucetich et al. (2012) Managing wolves on Isle Royale, icons of wilderness culture in a changing
world. George Wright Forum 29:126-147.
6
archives). Two of the four wolves that had been increased to approximately 5 moose/km2, a introduced by humans were killed or removed remarkably (perhaps unprecedented) high density after they became a public nuisance and the other for a naturally regulated moose population (Karns disappeared (Mech 1966), and deTinitive evidence 1998). With this high density the impact of moose 2
for the fate of the other two wolves does not exist . on the forest also rose to levels never previously 2
Ultimately, wild wolves Tlourished , and measured (McLaren and Peterson 1994).
controversy over moose overabundance on Isle Although the presence of CPV was not Royale largely ceased when wolves colonized the detected after 1990 (Peterson et al. 1998), the island (Peterson 1995). disease fundamentally altered wolf population Since their establishment on Isle Royale, dynamics for the next several decades (Wilmers et wolves have been the primary source of moose al. 2006). SpeciTically, the period after the wolf mortality, and moose have comprised more than crash was characterized by: (i) fewer wolves per 90% of wolves’ diet. In 1958 researchers began moose than the two decades prior to the human-­‐
studying the population dynamics of wolves and introduced disease (Fig. 3), and (ii) climatic moose on Isle Royale. Between 1958 and 1980 variation replacing wolves as the dominant wolf predation had a substantial impact on moose inTluence on moose dynamics (Wilmers et al. abundance and rates of browsing (McLaren and 2006). Moreover, wolf abundance was tied tightly Peterson 1994; Wilmers et al. 2006). to the abundance of old moose5 prior to 1980; but Then in the early 1980s the wolf after 1980 wolf abundance became unrelated to population crashed, declining 80%. The cause of abundance of old moose (Fig. 3, Vucetich and t h e c r a s h w a s a l m o s t c e r t a i n l y t h e c o m b i n e d inTluence of food limitation and a disease that had been i n t r o d u c e d b y h u m a n s , canine parvovirus (CPV, Peterson et al. 1998; Fig. 2).3,4
By the mid-­‐1980s the wolf population seemed to b e g i n m a k i n g a q u i c k recovery, but then declined again and remained in the low teens for the better part of a decade. With w o l f p r e d a t i o n Figure 2. Wolf and moose fluctua0ons, Isle Royale Na0onal Park, dramatically reduced, 1959-­‐2013. Red arrows point to wolf declines associated with the m o o s e a b u n d a n c e presence of canine parvovirus, a disease that humans brought to Isle Royale. See text for details.
2
See section 5 of this document for details.
3 After
CPV was suspected to be the cause of the crash, NPS staff decided not to vaccinate Isle Royale wolves because doing
so would have made it impossible to know if the disease was still present (antibody levels would be similar in response to
disease exposure or vaccination.) The decision was based on the value of scientific knowledge, not the wilderness value of
non-intervention (reference).
4
For additional details about canine parvovirus, see the appendix.
5
Old moose (>9 years of age) are an important source of food for the Isle Royale wolf population.
7
Peterson 2004). One plausible mechanism for these long-­‐lasting effects is the general tendency for some ecosystems to remain altered for long periods following a major perturbation (Wu and Loucks 1995; Beisner et al. 2003). Another plausible mechanism is that the population bottleneck caused by the disease led to elevated levels of inbreeding, which reduced the wolf population’s ability to control the moose population (Räikkönen et al. 2009). One long-­‐
lasting effect of the disease-­‐induced wolf reduction during the 1980s was a Tivefold increase in moose abundance that ended when the population crashed in 1996 (Fig. 2). Approximately two thousand moose (~75% of the population) starved to death in a four-­‐month period. The dramatic rise of moose abundance that coincided with the arrival of CPV and the subsequent collapse of the moose population in 1996, led to an altered age structure in the moose population that lasted for another 15 years (until about 2010). The altered age structure began with the substantial decline in birth rates of moose for several years following the crash. Those years of low birth rate led to a shortage of old moose by 2009. Because wolves cannot easily kill middle-­‐
aged moose, a shortage of old moose is associated with a shortage of food for wolves (Vucetich and Peterson 2004). The salient point is that the recent decline in wolf abundance is associated with a chain of events that coincide with the introduction of CPV by humans in the early 1980s. In addition to an altered age structure, total moose abundance declined by more than 50% between 2001 and 2011 (from ~1100 to ~500). These are the lowest estimates of moose abundance ever documented on Isle Royale, and they may play a role in the elevated extinction risk now facing wolves. The moose decline was likely caused by a set of three interrelated factors: wolf predation, a series of warm summers, and winter ticks (Dermacentor albipictus). In 2007, CPV was again detected in the wolf population, along with adenovirus, Anaplasma phagocytophilum, and West Nile6 . Human introduction is the most likely source of CPV and is at least plausibly, if not likely, the source of adenovirus and A. phagocytophilum. Although these diseases are not expected to impact the population dynamics of wolves, they Figure 3. Prior to 1980, when humans had introduced canine-­‐parvovirus, wolf abundance was well correlated to the abundance of old moose (dashed line), which are a main source of food for Isle Royale wolves. During the next two decades that rela0onship dissolved (solid line). Inbreeding depression, exacerbated by human-­‐introduced disease, is a plausible explana0on for the change (Wilmers et al. 2006).
6 More specifically, of six wolves tested in 2007, two had antibodies for CPV. In 2009, five wolves were tested for disease.
One had antibodies for adenovirus and two had antibodies for CPV. In 2012, two wolves were tested. One had antibodies for
A. phagocytophilum. Failing to detect antibodies for CPV in 2012 in two wolves may be not strong evidence that the disease is
absent, given its presence in 2007 and 2009. Canine anaplasmosis is caused by one of two gram-negative, obligate,
intracellular bacterial agents, A. phagocytophilum or A. platys. Infection with A. phagocytophilum, the species more commonly
associated with anaplasmosis, causes lameness and is often confused with Lyme disease. Anaplasmosis is likely spread by
ticks. A review of available evidence would likely show that reports of humans bringing ticks from the mainland to Isle Royale
has been on the increase in recent years. The adenovirus test is for type II (respiratory infection) antibodies, though there is
some cross reactivity with type I (infectious hepatitis).
8
could be detrimental to an isolated population with limited exposure or an inbred population. What is known is that the wolf population began declining when those diseases were detected. In particular, the population declined by 70%, from 30 to 8 wolves, between 2006 and 2013. Moreover, three of the island’s XX wolves died when they fell into a mineshaft in 200X. The mineshaft is an artifact of human activities from the 19th century. It is, at the very least, plausible that human-­‐introduced disease has played an important role in this most recent decline of wolves. Genetic deterioration The Isle Royale wolf population was founded in the late 1940s about 15 wolf generations ago. Analysis of mitochondrial DNA and the Y chromosome suggests that the population was originally founded by only one female and two males (Adams et al. 2011). The mean census size of the population has been ~24 wolves. In most years, the population includes 3 pairs of reproducing wolves. The effective population size of a population (Ne) quantiTies the rate of inbreeding for that population. The Ne for Isle Figure 4. The inbreeding coefficient for Isle Royale wolves, 1950-­‐2010 (Adams et al. 2011). The drama0c drop in the level of inbreeding that began in the late 1990s was the result of an immigrant wolf that arrived to Isle Royale by crossing an ice bridge.
Royale wolves is extremely low, i.e., ~3.8 (Peterson et al. 1998). The estimated inbreeding coefTicient has been as high as ~0.80 (Fig. 4). Maintaining inbreeding coefTicients below approximately 0.2 is generally considered a safe conservation standard (Frankham et al. 2007; Allendorf and Luikart 2003). The Isle Royale wolf population is, without doubt, highly inbred.
Moreover, the incidence of congenital deformities in the vertebral column of Isle Royale wolf population has been high and on the rise (Fig. 5 ; R a i k k o n e n e t a l . 2 0 0 9 ) . C o n g e n i t a l malformations that have been found include e.g. severe cervical anomalies, extra vertebrae and lumbosacral malformations (Raikkonen et al. 2009). A normal specimen has not been collected since 1994.
A p a r t i c u l a r k i n d o f d e f o r m i t y (lumbosacral transitional vertebrae, LSTV) that is Figure 5. The incidence of malforma0ons in Isle Royale wolves (1955-­‐2005) has been increasing over 0me (p=0.02). Each symbol represents the year of birth for a different Isle Royale wolves, with (1) and without (0) vertebral malforma0ons. The red curve is a logis0c regression curve and represents the increasing probability of having a malforma0on over 0me (Raikkonen et al. 2009). Since 2005, the vertebral remains of more than XX addi0onal wolves have been inves0gated. Each of those individuals exhibit vertebral malforma0on. 9
common among Isle Royale wolves (Figs. 6 and 7) has also been studied in other wolf populations. It tends to be rare among wolves in outbred wolf populations, more common among inbred wolf populations, and quite common among Isle Royale wolves (Raikkonen et al. 2009, 2013). The effect of these malformities on Titness is unknown. However, the kinds of vertebral malformations common among Isle Royale wolves are likely detrimental (Morgan et al., 1993; Morgan, 1999; Steffen et al., 2004; Flückiger et al., 2006). For example, domestic dogs (Canis lupus familiaris) with lumbosacral transitional vertebrae tend to suffer from cauda equina syndrome, CES (Morgan et al., 1993). CES entails injury to the cauda equina, the most caudal region of the spinal cord and associated nerve roots (Berzon and Dueland, 1979). The consequences of CES, which are independent of its etiology (Morgan et al., 2000), are variable and include paresis or paralysis; deTicits in placing reactions when Figure 6. The red line highlights a gross malforma0on (lumbosacral transi0onal vertebrae) in the posterior edge of the sacrum of an Isle Royale wolf. This and other vertebral malforma0ons observed in Isle Royale wolves are thought to be caused by inbreeding. 10
walking; deTicits in voluntary movement of the tail; loss of muscle tone causing weakness of the hind limbs and Tlaccidity of the tail, low back pain and incontinence (Morgan et al., 1993, 2000). Because of the clinical problems and genetic background associated with LSTV in purebred dogs, affected individuals are not recommended for breeding (Morgan et al., 1993; Wigger et al., 2009; Ondreka et al., 2013).
Several Isle Royale individuals exhibited a sacral process with strong illial attachment on one side and a process of lumbar nature on the other side. This condition weakens the sacroiliac joint, may accelerate degeneration of the disc and result in disc protrusions (Morgan et al., 2000). Such disc degeneration with dorsal protrusion is also a common cause of CES. Dogs exhibiting disc protrusion also tend to suffer low back pain and lameness (Steffen et al., 2004). Asymmetrical sacroiliac attachment can also be associated with pelvic obliquity that can result in gait irregularities (Larsen, 1977) and detrimental development of the hip joints (Morgan et al., 2000).
Some have expressed doubt about the relationship between LSTV and inbreeding, citing an unpublished analysis suggesting that LSTV is common in an outbred population of wolves in Wisconsin (S. Ware, pers. comm.). Though we have been told of this analysis, it has not been, to our knowledge, prepared as a formal analysis for review by scholars with relevant expertise. An important concern is that the frequency of LSTV in Figure 7. A par0cular kind of malformity (lumbosacral transi0onal vertebrae), is drama0cally more common among Isle Royale wolves than wolves in outbred popula0ons (Raikkonen et al. 2009).
a population depends on the standards used to determine whether any particular specimen should be classiTied as exhibiting LSTV (Lappalainen et al 2012, Ondreka et al. 2013). Even if the high incidence of malformities in Isle Royale wolves were discounted, the tendency for those malformities to have increased over time is clearly suggestive of inbreeding depression (Fig. 7). Most importantly, if those malformations were overlooked entirely, the evidence that Isle Royale wolves have been exhibiting high rates of inbreeding and inbreeding depression is overwhelming (Figs. 4 and 8).
In 1997 a male wolf (M93) immigrated from Ontario to Isle Royale by walking across an ice bridge. The inbreeding coefTicient plummeted in the years immediately following his arrival, but then began to rise quickly again (Fig. 4). Within 2.5 generations of his arrival, he was related to every individual in the population and his ancestry Figure 8. The drama0c rise in ancestry of the immigrant wolf is defini0ve evidence for how severely impaired Isle Royale wolves had become due to inbreeding (Adams et al. 2011). The rise in ancestry quan0fies the extent to which the immigrant’s lineage outcompeted the na0ve Isle Royale lineage. The rela0ve performance of the two lineages is a direct measure of the two lineage’s rela0ve fitness.
constituted 56 per cent of the population (Fig. 8). The superior performance of M93 and his lineage, compared to the performance of native Isle Royale wolves is unequivocal evidence that these wolves have been suffering signiTicant, if not severe, inbreeding depression (Hedrick et al. 2011). L. David Mech, an inTluential wolf biologist from the U.S. Geological Service, has been outspoken about his ardent belief that Isle Royale wolves are not suffering in any signiTicant way from inbreeding (Mech and Cronin 2009, Mech 2013). His belief and the premises upon which they are based are well known to be at odds with leaders in the scientiTic study of conservation genetics (P. Hedrick, pers. comm.). The disparity between his beliefs and the community of conservation geneticists is relevant because L. D. Mech’s misunderstanding of conservation genetics lies at the root of his vocal belief that the NPS should refrain from implementing genetic rescue with the Isle Royale population. L. D. Mech’s misunderstandings are not moot. For example, he was one of four presenters at a public forum held on the topic of whether or how to conserve Isle Royale wolves7. While this issue depends critically on a proper understanding of conservation genetics, none of the presenters had expertise in that Tield. Phil Hedrick, a world authority in the Tield of wolf genetics, had agreed to participate in that forum, but was not invited. That forum included a survey of observers from the general public, who had witnessed the forum. Presumably that survey will be an important element of the NPS’s decision-­‐making process. Because L.D. Mech is an inTluential voice, one should expect that his misunderstanding of the relevant science has affected the outcome of that survey. Finally, the immigrant wolf, M93, arrived to Isle Royale immediately after the moose population had crashed (Fig. 9). That decline was due, in large part, to a severe winter and was unrelated to wolf predation. That reduced availability of prey represented a challenging 7
The forum was held in June 2013 in Minneapolis, Minnesota and had been organized by the National Parks Conservation
Association.
11
Figure 9. The gene0c rescue event that occurred with the arrival of immigrant M93 began in 1997, and that period is highlighted in gray. Panel (a) shows how that rescue took place immediately following the crash of the moose popula0on. Panel (b) shows how the moose-­‐to-­‐wolf ra0o, an important predictor of food availability for Isle Royale wolves (Vuce0ch et al. 2002), also crashed just as the rescue took place.
environment in which Isle Royale wolves had to persist. Their persistence through that period was almost certainly aided by the genetic rescue that occurred with M93 crossed an ice bridge in 1997 (Adams et al. 2011). Reproductive failure
There is no evidence that Isle Royale wolves reproduced in 2012 (Vucetich and Peterson 2012, 2013). As of July 1st, 2013, no reproduction had been detected for the year 2013. L. D. Mech has raised the concern that reproductive failure is common in wolf populations and observing reproductive failure on Isle Royale is not evidence that Isle Royale wolves 12
Figure 10. The incidence of ice bridges to Isle Royale (1959-­‐2013) has been decreasing over 0me (p<0.01). Each symbol represents a different year with (1) and without (0) ice bridges. The red curve is a logis0c regression curve and represents the decreasing probability of ice bridges. During the mid 20th century, ice bridges occurred more frequently than 8 out of every 10 years. By 2013, they occur less frequently than once every 15 years.
face critical risk of extinction due to inbreeding depression. Two observations indicate how this concern is misplaced. First, if evidence about reproduction were overlooked entirely, there is overwhelming evidence that Isle Royale wolves suffer signiTicant, if not severe, inbreeding depression and face considerable risk of extinction. Second, reproductive failure is absolutely and unequivocally uncommon on Isle Royale. Reproduction has been monitored every year for the past 42 years. In that time, 2012 is the Tirst year with no evidence that wolves had reproduced. The Tirst observation clearly makes the second observation relevant and noteworthy. The importance of ice bridges Wolves colonized Isle Royale, on their own, sometime between 1948 and 1950. Genetic analyses also indicate that a lone male wolf immigrated to Isle Royale and mated with Isle Royale wolves on one to three occasions between 1950 and 1997 (Adams et al. 2011). Moreover, an entire pack of wolves came to Isle Royale in 1967. After being attacked by resident, Isle Royale wolves the pack returned to the mainland8. Each of these events occurred when wolves crossed an ice bridge connecting Isle Royale to the mainland.
Anthropogenic climate warming has greatly reduced the frequency and duration of stable ice bridges (Fig. 10). During the 1960s stable bridges formed in most years and lasted for several weeks to well over a month. Now ice bridges are rare. Lake Superior is expected to be ice free by 2040 (Austin and Colman 2007). The frequency at which wolves seem to have used ice bridges in the past and the dramatic reduction in frequency of ice bridges suggests that humans have been and continue to impair the likelihood that wolves would mitigate rates of inbreeding by immigrating to Isle Royale. The loss of ice bridges also mean that wolves are very unlikely to re-­‐colonize Isle Royale, should the 8
population go extinct. Conclusion
Isle Royale wolves face considerable risk of extinction. They are severely inbred (Fig. 4). They suffer from signiTicant, if not severe, inbreeding depression (Figs. 6-­‐9). For the past two years (2012 and 2013), predation rates were the lowest that have ever been observed. During that same period of time, the moose population has increased by ~70%. As such, the inTluence of predation has been essentially nil. It is at least plausible, and may be likely, that diseases brought by humans (Fig. 2) have exacerbated rates of inbreeding, the impact of inbreeding depression, and the risk of extinction that wolves currently face. It is at least plausible, and may be likely, that anthropogenic climate change has been and continues to impair the likelihood that wolves would mitigate rates of inbreeding by immigrating to Isle Royale and would make their re-­‐colonize Isle Royale a very unlikely event (Fig. 10). Except one black wolf remained. It continued to live on Isle Royale for another five year. But it never reproduced.
13
2. AS LONG AS THERE ARE MOOSE,
THERE SHOULD BE WOLVES9
We structure this analysis by identifying and describing some key values that would be affected by any decision about how to manage Isle Royale wolves. Afterward describing these values, we evaluate whether they are best honored by preserving predation processes on Isle Royale or by not intervening. The value of non-­‐intervention. A central management principle of wilderness policy is the principle of non-­‐intervention, which is sometimes casually characterized as: “not intervening, so that nature can take its course.” As a central principle of wilderness, non-­‐intervention is not valuable for its own sake; instead it is thought to be valuable as a means toward two critical ends. First, it can prompt an attitude of humility that mitigates pathological obsessions to control nature (Meffe and Holling 1996; Landres 2010). Second, using language of the U.S. Wilderness Act 1964, non-­‐
intervention can help maintain natural conditions and the primeval character of landscapes that have not already been inTluenced by human activities10. According to well-­‐established wilderness policy, non-­‐intervention is not, in general, a preferred management option when “nature’s course” has been altered by humans. In such cases, intervention is commonly adopted in an effort to mitigate human inTluence (Dawson and Hendee 2008; Cole and Yung 2010). During the past three decades the wolf population has been affected by disease and moose population decline, which was inTluenced by predation, ticks, and climate warming. Humans had a nontrivial hand in all of these inTluences. If wolves were to go extinct, it would be plausible to conclude that humans had exacerbated the extinction risk of wolves during the past three decades and that humans have signiTicantly reduced the chances of natural recolonization. Given that intervening to mitigate human inTluences is a wilderness value, intervention in the Isle Royale case would enhance and honor wilderness values of Isle Royale. O n e m i g h t o b j e c t a n d s u g g e s t , hypothetically, that Isle Royale wolves would go extinct due to inbreeding and chance demographic events (e.g., skewed sex ratio) that are likely to occur naturally and inevitably on a small island. However, a fundamental principle of extinction is that it is not in general the result of a single cause. Extinction is almost always the result of an interrelated web of both proximate and ultimate causes. Even if inbreeding or natural random chance occurrences were part of the extinction process, the salient conclusion remains: Human actions importantly increased extinction risk and decreased the chance of re-­‐colonization. The value of wilderness character. Preserving the “wilderness character” of a landscape is another fundamental value of wilderness management, particularly for Isle Royale National Park (U.S. NPS 1999). Wilderness character arises from the properties of a landscape that evoke a feeling or emotion that the landscape is wild and primeval. Wilderness character is also a special kind of ‘sense of place,‘ which is formed when the natural history, culture, and geography of a place commingle in our minds and form the stories – lyrical stories and scientiTic stories – that deTine a place. Sense of place and wilderness character are 9
This section is adapted from Vucetich et al. (2012) Managing wolves on Isle Royale, icons of wilderness culture in a changing
world. George Wright Forum 29:126-147.
10
The US Wilderness Act of 1964 says: “An area of wilderness is further defined to mean… an area of undeveloped Federal
land retaining its primeval character and influence… which is protected and managed so as to preserve its natural conditions.”
14
critical because they provide the points of connection between a place and a person’s knowledge, emotions, and values.
Wolves are a critical component of Isle Royale’s wilderness character – not merely the presence of wolves, but the interactions among wolves, moose, and the forest, all in the absence of any hunting or logging by humans. This condition is, on our planet today, rare, special, and critical for evoking a feeling that Isle Royale’s landscape is wild and primeval11. Wolves and their connections provide the most important and widely appreciated narratives that create a wilderness sense of place for this island. This importance is reTlected in NPS policy, interpretive activities, and widespread interest among park visitors, scientists, and supporters of wild places (see Appendix 2 for details). For Isle Royale, wolves are the icons of wilderness culture. Therefore, allowing wolves to remain extinct on Isle Royale would signiTicantly wound Isle Royale’s wilderness character and important points of connection between people and Isle Royale. It may seem odd that non-­‐
intervention would conTlict with the preservation of a land’s wilderness character. However, this ironic juxtaposition is not odd, so much as it is the result of a tragedy: humans have reduced the planet’s unexploited landscapes to small remnants in remote places. The value of ecosystem health. – In the United States, the preservation of ecosystem health is also broadly appreciated as a central value of wilderness (Nelson 2009a, 2009b). Ecosystem health has been deTined, roughly, as the structure, function, composition, and resilience of an ecosystem that was native prior to the modern era (Rapport et al. 2002). Ecosystem health is a coherent blend of normative and objective concepts (Nelson 2009a). That is, society, led by the voices of conservation leaders, has indicated that structure, function, composition, and resilience are the ecosystem properties that have moral value; and, science is able to objectively measure and evaluate these properties. The meaning of ecosystem health is both Tlexible enough to be applied to any particular place or time and concrete enough to make it a useful platform for management.
A great deal of conservation science afTirms that ungulate overabundance is a widespread and severe threat to ecosystem health, and that top predators, like wolves, are vital components of ecosystem health for limiting ungulate abundance (Miller et al. 2001; Beschta and Ripple 2009; Estes et al. 2011). North American national parks, in particular, have been challenged by this fact (e.g., Rocky Mountain, Great Smoky Mountains, and Yellowstone national parks). In Canada’s Gros Morne National Park the loss of wolves resulted in moose overabundance that degraded 44% of that park’s forests (Woodley 2010). The health of island ecosystems seems particularly vulnerable to ungulate overabundance in the absence of predators, for example at Anticosti Island, Quebec (Potvin et al. 2003) and North Manitou Island of Sleeping Bear Dunes National Lakeshore (Case and McCullough 1987). In several parks where wolves have (or had) been excluded, hunting or culling of ungulates has been, with great controversy, considered or mandated (e.g., Rocky Mountain and Yellowstone national parks). Unless possibly very high rates of moose harvest were mandated,12 allowing wolves to be 11
This value is related to another traditional value of wilderness, i.e., wilderness as a sanctuary for nature (see Leopold 1949,
Sanders 2008). Wolves on Isle Royale have been and continue to be the only wolves in North America who can live their lives
without the risk of being legally hunted or poached. That Isle Royale might be a sanctuary for wolves had also been a
motivation for those who had originally considered reintroducing wolves to Isle Royale in 1940s and 1950s (unpublished
correspondence, Michigan Technological University archives).
12
Although non-extraction is an important principle of wilderness, hunting (and fishing) is permitted in many federally
designated wilderness areas. While it may seem far-fetched to be concerned that the loss of wolves would lead to hunting Isle
Royale moose, that prospect has been considered in cases where the absence of top predators led to ungulate
overabundance in a national park (e.g., Theodore Roosevelt National Park, Rocky Mountain National Park).
15
lost from Isle Royale would signiTicantly diminish its ecosystem health.
A detractor of this perspective might suggest that using “ecosystem health” in this way to justify wolf reintroduction disguises a romantic and outdated desire to preserve “vignettes of primitive America,” and that wolves were a critical part of IRNP’s ecosystem health from ca. 1950 until the time of their extinction, but not afterward. Certainly, top carnivores were an important aspect of historic conditions. This does not mean, however, that maintaining and restoring top carnivores to places where large herbivores live represents maintaining “vignettes of primitive America.” Instead, top predators are a basic principle of ecosystem health (Estes et al. 2011). A detractor might also object by Tirst citing NPS management policies (2006) which mandates “maintain[ing] all the components and processes of naturally evolving park ecosystems, including the natural abundance, diversity, and genetic and ecological integrity of the plant and animal species native to those ecosystems [and recognize] natural change… as an integral part of the functioning of natural systems” [italics added]. With this policy in mind, a detractor might assert that the deTining characteristic of Isle Royale’s ecosystem health is its small, isolated nature, where colonization by wolves and moose are rare “accidents” and extinction is a natural process. Isle Royale is a dynamic place, and wolves and moose have been a part of Isle Royale’s history for only a short time. For these reasons, the argument would go, losing wolves from Isle Royale leaves the place no less healthy than it had been before their arrival. The weakness of this argument may be Tirst recognized by noting that wolf–ungulate–
vegetation interactions used to be a dominant set of ecological relationships throughout much of North America. By the 21st century, however, humans have restricted such relationships, operating in the absence of human exploitation, to very rare and small remnants. The detractor’s perspective pits the value of one natural process 13
(extinction on small islands) against another (predation) (Peterson and Krumenaker 1989; Peterson 1995). The detractor’s position overlooks the process of wolf predation, which is essential to the health of Isle Royale’s ecosystem.
The weakness of the detractor’s position arises from the concept of natural being fraught with debilitating dilemmas that have remained intractable despite being considered for more than two millennia (Desjardins 2000; Cole and Yung 2010). The concept of natural is increasingly difTicult to make sense of because of human impact on the planet.
Because of these problems with the concept of natural, Parks Canada recently replaced “naturalness” with “ecological integrity”13 as a general management objective for their natural areas (Woodley et al. 2010). A speciTic example of this attitude is likewise reTlected in the general management plan for IRNP (1999), which indicates that “preserving and protecting the park’s wilderness character, … natural resources… and ecological processes” is one of the park’s purposes and that “preserve ecological integrity of Isle Royale” is one of the park’s priorities (NPS 1999). Again it seems ironic to pit the value of non-­‐intervention and natural processes (like extinction on small islands) against the value of ecosystem health. However, the tragedy is having reduced the planet’s unexploited areas to small remnants, resulting in the need to actively maintain ecosystem health in these tiny remnants. This concern is aptly captured by: “What escapes the eye... is a much more insidious kind of e x t i n c t i o n : t h e e x t i n c t i o n o f e c o l o g i c a l interactions” (Janzen 1974).
The value of science. The primary scientiTic mission of the Isle Royale wolf–moose project is to document and understand predation and herbivory – two of the most important ecological relationships on the planet. Isle Royale’s biogeography is critically unique for this mission. “Ecosystem integrity” and “ecosystem health” are essentially synonymous.
16
The island’s isolation means that Tluctuations of wolves and moose are caused almost entirely by births and deaths, not immigration and emigration. Isle Royale is also the only location on the planet where wolves and moose interact in the absence of other important predators and prey, such as coyotes, deer, and bears. Studying simpliTied food webs is critical to ecologists’ understanding of nature. Perhaps most importantly, the wolves, moose, and vegetation on Isle Royale are not hunted or logged. This circumstance is very rare on the planet today.
Wilderness areas are uniquely valuable to science as places for establishing baselines of ecosystem health that can be applied in areas far beyond wilderness. These baselines cannot be established overnight, as they require long-­‐term research. Long-­‐term research is not only rare, it is valuable for its distinctive ability to help us better understand how ecosystems are affected by unexpected events, rare events, and multicausal relationships (Turner et al. 2003). The Isle Royale wolf–moose project is the longest study of any predator–prey system in the world. The project has made valuable scholarly contributions on a wide range of topics, including population biology of wolves (e.g., Vucetich and Peterson 2004), effect of wolf predation on moose (e.g., McLaren and Peterson 1994, Vucetich et al. 2011), effect of climate and disease on population dynamics (e.g., Post et al. 1999, Wilmers et al. 2006), the nature of extinction risk (e.g., Vucetich et al. 1997, 2009), the effect of genetic rescue on population dynamics (e.g., Adams et al. 2011), the nature of inbreeding depression (e.g., Räikkönen et al. 2009), connections between individual life history and population dynamics (Peterson et al. 1984), social behavior of wolves (Vucetich et al. 2004), the effect of the U.S. clean air and water legislation on mercury pollution (Vucetich et al. 2009), the role of predation in nutrient cycling (Bump et al. 2009), the ecology of arthritis in moose (Peterson et al. 2011), the relationship between ecological science and environmental ethics (Nelson et al. 2010; Vucetich et al. 2010), and the relationship between ecological science and sociology (Gore et al. 2011). Papers from the wolf–moose project have been cited more than 1,200 times during the past 10 years. The scientiTic value of the wolf-­‐moose project was recently afTirmed by an independent panel of scientists commissioned by the National Park Service who reviewed the state of science in Isle Royale National Park (Schlesinger et al. 2009).14 Allowing wolves to be excluded from Isle Royale would cause the end of wolf-­‐moose research and its extensive outreach program. SuperTicially, one might think the loss of wolves would simply cause the wolf–moose project to become a moose–vegetation study. While studies focusing on three trophic levels are rare, studies focusing on ungulate herbivory in the absence of top predators are extremely common. Moreover, the approach and methods used to conduct state-­‐
of-­‐the-­‐art herbivory research are very different from the methods appropriate for studying interactions across three trophic levels. As such, the Isle Royale wolf–moose project is in no position to effectively compete for funding from the US National Science Foundation, the loss of which would be the death of the project. In 2009 and 2010, the wolf–moose project proposed research to NPS that would expand the moose-­‐
vegetation component of the research. NPS chose to not fund that research. There is little reason to think that the longest study of any predator–prey 14
The number two “Priority Recommendation” of this panel was “Maintain financial support for and expansion of ongoing
studies of moose–wolf dynamics at Isle Royale.”
17
system in the world would survive the loss of wolves from Isle Royale.
Should science ever, in principle, trump wilderness values in a wilderness area? Well-­‐
established wilderness policy clearly indicates the answer to this question is, “yes.”15 The question at stake here is: Should one of the longest and most prominent research projects to ever take place in a federally designated wilderness be sacriTiced for the far-­‐from-­‐solid claim that doing so might afTirm the value of non-­‐intervention?
The value of education. – Wilderness policy also recognizes the vital role that education about “wilderness character, resources, and ethics” play in maintaining values that promote healthy relationships with nature (§6.4.2 in NPS 2006). The educational mission of the Isle Royale wolf–
moose project is to use scientiTic discoveries about the wolves and moose of Isle Royale as a basis for “generat[ing] a sense of wonder toward nature in as many people as possible,” a sense of wonder that would inspire a caring relationship with nature (Vucetich 2010). The mission is not only true to the project’s science, but it is informed by inclusion of an environmental philosopher (MPN) as part of the wolf-­‐moose project. To this end, associates of the wolf–moose project disseminate knowledge to the general public through a vigorous outreach program that includes books, DVDs, annual reports, a website, pieces of art, museum exhibit displays, and public presentations delivered to thousands annually by the project principal investigators and other associates, and opportunities for members of the general public to volunteer for the research project (see Appendix 3 for details). The extent of 15
outreach associated with the wolf–moose project and sophistication of its purpose is rare among research projects of any kind. Wilderness policy also recognizes that recreation is an important value that is sometimes associated with compromising the wilderness value of non-­‐intervention (§6.4.3 in NPS 2006). Hiking trails, boat docks, and sleeping shelters (and the machinery and infrastructure necessary to maintain them) are examples of such concessions. The wolf–moose project also represents an important form of recreation. For many people, participating in the wolf–moose project’s outreach activities represent a particularly deep kind of recreation, an opportunity to re-­‐evaluate and subsequently re-­‐
create their relationship with nature.
Synthesis. – Should the wolves of Isle Royale go extinct, human response involves Tive principal values: non-­‐intervention, wilderness character, ecosystem health, science, and education. Failing to reintroduce wolves would: • dismiss the value of science and education by resulting in the end of a long-­‐term research project that is globally signiTicant, unique, and irreplaceable.
• more likely denigrate the value of non-­‐
intervention because this value is contingent on humans not having impaired the wolf population’s viability or the chances for subsequent recolonization; human activities have impaired these processes.
• diminish the island’s wilderness character and ecosystem health;
For these reasons, failing to reintroduce wolves would degrade the wilderness value of Isle Royale, “Scientific activities are to be encouraged in wilderness. Even those scientific activities (including inventory, monitoring, and
research) that involve a potential impact to wilderness resources or values (including access, ground disturbance, use of
equipment, and animal welfare) should be allowed when the benefits of what can be learned outweigh the impacts on
wilderness resources or values.” ( §6.3.6.1 of U.S. NPS 2006). Additionally, Isle Royale’s General Management Plan (1999)
states that two of the park’s five purposes are not only to “preserve and protect the park’s… natural resources and ecological
processes” but also to “provide opportunities for scientific study of ecosystem components and processes.”
18
and wolf reintroduction is an appropriate way to honor that value. Lingering concerns about the inappropriateness of intervening in a wilderness are further molliTied by the evolution of our understanding of wilderness. That is, ecosystem health may well be superseding non-­‐intervention as the central value of wilderness (Cole and Yung 2010).
These perspectives are complemented by sociological research indicating that an “overwhelming majority” of Michigan residents do not believe that allowing “nature to take its course” is an adequate reason to allow the extinction of Isle Royale wolves and support the belief that Isle Royale wolves should be maintained should they begin to disappear from the park.16
Would reintroducing Isle Royale wolves because of their contributions to ecosystem health in boreal forests open a kind of Pandora’s box requiring one to consider introducing black bears which also prey upon moose in many boreal forest ecosystems, and consider reintroducing lynx and caribou to IRNP for their contributions to ecosystem health? Perhaps. There would be nothing wrong with conducting an analysis like t h a t p r e s e n t e d h e r e t o c o n s i d e r t h e appropriateness of introducing or reintroducing these species to Isle Royale. The development of such arguments is beyond the scope of this essay, except to mention a few considerations. First, the ecology of black bear predation on moose differs substantially from the ecology of wolf predation. If wolf predation is essential for ecosystem health where moose live, then bear predation is unlikely a substitute for wolf predation. Consequently, if a robust argument could be developed for black bear introduction 17, it is difTicult to imagine how that would end up being an argument against wolf reintroduction. Similarly, if a robust argument could be developed for establishing a lynx population, such an argument is unlikely to be an argument against wolf reintroduction. Caribou persistence on Isle Royale is unlikely in the presence of wolves (Cochrane 1996). As such, an argument for caribou reintroduction may well be an argument against wolf reintroduction. If so, one would have to assess whether the value of caribou on Isle Royale would outweigh the value of wolves. Both species probably have similar value in terms of wilderness character. However, the scientiTic and educational value of caribou on Isle Royale is likely less than the scientiTic value of wolves on Isle Royale (because the wolves have been studied for over half a century). Introducing caribou, rather than wolves, would add a second large ungulate to an ecosystem lacking a top predator. While these considerations do not represent a complete argument, they do suggest, at least prima facia, that a complete argument would support wolf reintroduction.
General lessons. – Our ideas about what wilderness is, and why wilderness is valuable, change over time. During the Tirst half of the 20th century, wilderness philosophy focused on woodcraft, a principle of self-­‐sufTicient living in the wilderness characterized by experiences like utilizing trees for temporary structures and Tires. By the mid-­‐20th century wilderness leaders grew to realize that the growing number of people wishing to have this kind of wilderness experience in a diminishing number of wilderness areas would result in a devastating loss of wilderness. From this concern grew a new philosophy of wilderness, a philosophy associated with the principles of “leave-­‐no-­‐trace,” and along with it the principle of non-­‐intervention (Turner 2002). By the early 21st century, wilderness areas had been reduced even further and human impacts o n t h o s e a r e a s h a d b e c o m e p e r v a s i v e . 16
Specifically, 62% of surveyed residents strongly or moderately disagreed with the statement “we should let nature take its
course even if wolves start to disappear from Isle Royale National Park”, and 73% of respondents strongly or moderately
agreed with the statement “wolf numbers should be maintained in Isle Royale National Park if they start to disappear from the
park” (Kellert 1990, pages 57 and 61).
17
Other considerations, beyond the scope of this essay, suggest it is doubtful that a robust argument could be developed.
19
Anthropogenic climate change and exotic species have altered the course of nature in nearly every protected area. Consequently, the principle of managing for naturalness is becoming less coherent, and the value of non-­‐intervention as a means of preserving naturalness is becoming less useful. The transition from naturalness to ecosystem health as a basis for understanding the value of wilderness was reTlected in the life-­‐long development of Leopold’s thought on wilderness (Nelson 2009b). This transition was fully articulated by wilderness scholars from the 1980s 20
to 2000s (Callicott and Nelson 1998; Nelson and Callicott 2008). By 2010, these ideas were being appreciated by land management agencies including the U. S. National Park Service (Cole and Yung 2010, Harmon 2010, Parsons 2011). The emerging challenge is to better understand the meaning of ecosystem health in a world that appears committed to anthropogenic climate change, species invasions and extinction, and increasing resource extraction (Vucetich and Nelson, in press). 3. CONSERVATION IS PREFERABLE TO RESTORATION
Previously, we presented an analysis (i.e., Vucetich et al. 2012) suggesting that the “do nothing” option would be undesirable because wolf predation should be present on Isle Royale so long as moose inhabit the island and so long as ecosystem health is a priority for the National Park Service. On May 9th, 2013, the New York Times published an editorial that we authored18 , within which we stated that genetic rescue was preferable to reintroduction. Here, we explain the reasoning behind this perspective. The explanation involves considering how genetic rescue and reintroduction would each relate to the value of ecosystem health, public narrative, and opportunities to develop new conservation knowledge. The objective of genetic rescue is conservation and the objective of reintroduction would be ecological restoration. As such, the explanation we offer may be useful in considering a much broader issue, which is the relative value of conservation and restoration. The term ‘restoration’ refers to two concepts – ecological restoration (Young et al. 2005) and genetic restoration (Hedrick 2005) – that are as different from each other as they are each important. Exogenous inCluences Maximizing opportunities for the development of scientiTic knowledge is not the primary purpose of National Parks and wilderness areas. It is, however, an important value of such areas (National Research Council 1991; Arcese & Sinclair 1997; Sinclair 1998; Nelson & Callicott 2008;). As such, there is value in assessing whether conservation (genetic rescue) or ecological restoration (reintroduction) would offer a better chance of developing more signiTicant scientiTic knowledge. Before evaluating that prospect directly, we address a common, but mistaken, assumption: knowledge gained from Isle Royale’s wolves and moose has been critically attributable to the absence of human inPluences and other exogenous factors. This presumption is impressively false. The special opportunities that Isle Royale represents for developing knowledge are certainly attributable to its small geographic size, simplicity of its food web, limited inTluence of immigration and emigration dispersal on the demography of wolves and moose, and the absence of exploitation or harvest at any level of the food chain (wolves, moose, or the forest). However, as explained below, the two most important scientiTic insights gained from the wolves and moose of Isle Royale are attributable to human inTluence and an exogenous event. First, one of the most important aims in ecology is to understand the extent to which ecological communities are governed by the top-­‐
down forces of predation, compared to other forces such as climate and the bottom-­‐up forces of forage abundance. Wilmers et al. (2006) demonstrates how the Isle Royale system had been dominated by top-­‐down processes for an extended, two-­‐decade period (1960s and 70s) and then suddenly switched to being dominated by climatic factors for the next two decades (1980s and 90s). One might think that observing a strong top-­‐down signal for two decades would provide a solid basis for concluding that a system is governed by top-­‐down processes, unless one were to observe an opposing trend for the next two 18 www.ny0mes.com/2013/05/09/opinion/save-­‐the-­‐wolves-­‐of-­‐isle-­‐royale-­‐na0onal-­‐park.html?_r=0. While we authored this editorial, we regret that the printed version of the editorial suggests that wolves should be conserved because of some “Balance of Nature” that ought to be preserved. Balance of Nature is an outdated and misleading concept. We also regret that the printed version did not offer a reason why we prefer gene0c rescue to reintroduc0on. These deficiencies were the result of last-­‐ minute editorial decisions by New York Times editors. 21
decades. Because few systems are studied in sufTicient detail for more than a few years, the Isle Royale case is an important cautionary tale for claims about the inTluence of predation in other ecosystems. The critically salient detail, in this case, is that a wolf disease, brought by humans, triggered the shift from top-­‐down control to climate control (Wilmers et al. 2006). Ultimately, human inTluence triggered one of the most important events in the entire history of wolves and moose on Isle Royale (see also Vucetich and Peterson 2004).
Another fundamental concern in ecology is to better understand how genetic processes inTluence ecological processes. In a conservation context, an important interest is to better understand how small populations of conservation concern are beneTicially affected by the genes brought to a population by immigrants, a process known as genetic rescue. Adams et al. (2011) documented the consequences of a genetic rescue event when, in 1997, a wolf from Canada crossed an ice bridge to Isle Royale and became a resident breeding wolf.
While the immigrant might have been expected to result in improvements to survival, recruitment, or other demographic vital rates of the population (Tallmon et al. 2004), no signiTicant improvements were observed. However, the immigrant arrived just as the moose population crashed (in large part due to a severe winter). The diminished food supply obscured a demographic response from infusion of new genetic variation. Nevertheless, the immigrant’s genes spread throughout the population. Within two and a half generations (~10 years) more than half of the genetic ancestry in the Isle Royale wolf population descended from that single immigrant. The extent to which the immigrant and his lineage outcompeted the native lineage of Isle Royale wolves is unequivocal evidence for how severely the Isle Royale population had been suffering from inbreeding depression. Had the immigrant not arrived, the Isle Royale wolf population would have faired much worse, perhaps even having gone extinct by the turn of the 21st century. 22
Adams et al. (2011) provides several general lessons for conservation (Hedrick et al. 2011). For example, genetic rescue may be importantly beneTicial without improving the demography of a population, if that population is also living in a deteriorating environment. In such cases, the beneTicial inTluence of genetic rescue would be best indicated by a statistic known as genetic ancestry, which quantiTies the spread of the immigrant’s genetic contribution in the population.
Wilmers et al. (2006) and Adams et al. (2011) are important for demonstrating how human inTluence and exogenous events have resulted in some of the most important discoveries related to Isle Royale wolves. As such, it is inappropriate to think that conservation (genetic rescue) would, because it is an exogenous, human-­‐
caused event, diminish the special opportunities that Isle Royale has provided in the past for learning about nature. ScientiCic opportunity
To judge whether conservation (genetic rescue) or ecological restoration (reintroduction) would offer a better chance of developing more signiTicant scientiTic knowledge, three considerations seem relevant. First, the demography of Isle Royale’s wolves and moose has been understood by assessing population abundance in relationship to vital rates (e.g., survival, recruitment, kill rates, predation rates, etc.) and environmental variables. The opportunities for conducting those assessments are equal under both genetic rescue and reintroduction.
Second, reintroducing wolves after allowing them to go extinct would allow for documenting the precise timing and demographic details of one speciTic extinction event. Those details are known to be powerfully inTluenced by demographic stochasticity (Caughley 1994). In other words, the population might fall from low numbers to zero because of lack of reproduction or chance mortality events or skewed sex ratio, and that could occur in four years, or a couple years earlier, or later. The observations that could be made by observing Isle Royale wolves fall to extinction would not discriminate between any competing hypotheses about how extinctions occur. Given what is known about the stochastic processes associated with demographic (Vucetich & Waite 1998; Lande et al. 2003) and genetic (Lynch 1988; Lacy et al. 1996; Lacy & Ballou1998) elements of extinction, essentially no insight can be gained about any general principle of extinction by observing the demographic details of any single small population in the late stages of the extinction process. Third, genetic rescue is a potentially valuable conservation tool for many populations and species of conservation concern throughout the world (Tallmon et al. 2004; Hedrick and Fredrickson 2010). Genetic rescue, as a conservation tool, is also not adequately understood. The best opportunities to evaluate genetic rescue require careful monitoring of the population’s demography for many years before and after a genetic rescue event. Those opportunities are rare, but currently present in the case of Isle Royale wolves. This perspective indicates how genetic rescue would almost certainly lead to more scientiTic insight than reintroduction. There is no doubt that either action (conservation or ecological restoration) would result in the development of new knowledge. Nevertheless, there exist several hundred very well documented cases of monitoring the effects of inbreeding (Hedrick and Kalinowski 2000)., Genetic rescue, on the other hand, has been monitored carefully in fewer than about seven instances (Adams et al. 2011). For these reasons, genetic rescue would generate more signiTicant knowledge for conservation and ecology.
Ecosystem health & the continuity of predation
Reintroducing Isle Royale wolves after being allowed to go extinct would result in a greater risk of creating a discontinuity in predation. The inTluence of wolf predation on Isle Royale was already effectively nil in 2012 and 201319 . The population could, plausibly, take another four years to go extinct, and another year to be reasonably sure that extinction has occurred. Despite best intentions, another year (or perhaps many more) could plausibly pass in the logistical, budgetary, and administrative preparations that would precede reintroduction. A Tirst attempt at reintroduction could fail before predation processes are restored, and a reintroduced population might require a few years to establish territorial packs and become large enough to result in signiTicant rates of predation (Vucetich et al. 2011). The point is, restoring predation after allowing it to be lost could easily result in a decade-­‐long period during which predation is effectively absent from Isle Royale. In a decade, a moose population growing unimpeded could more than quadruple in number, which would signiTicantly alter Isle Royale’s vegetative community and set the stage for yet another moose eruption followed by catastrophic collapse from starvation, as occurred in 1934 and 1996.
Discontinuity in predation is signiTicant because restoring predation after its absence does not necessarily restore an ecosystem (e.g., Schmitz 2004). For example, the absence of wolf predation in Yellowstone allowed elk to outcompete beavers, greatly reducing the abundance of willow and beaver. The resulting alterations to hydrology appear to be not readily reversible, even after restoration of wolves (Marshall et al. 2013). On Isle Royale, beaver abundance has increased during the past several years as predation rates have declined (Vucetich and Peterson 2013). It is reasonable to expect that trend to continue so long as there is a discontinuity in predation processes, and to expect the trend to be reversed after predation is restored. That Tluctuation in 19 During 2012 and 2013, annual preda0on rate was only a third of the long-­‐term average. In par0cular, annual preda0on rate was 3.3% and 2.4% in 2012 and 2013, respec0vely. Average preda0on rate on Isle Royale has been 9.9% (interquar0le range = [6.2% ,11.7%]). Preda0on rate is the propor0on of moose that die from preda0on. 23
abundance would likely be associated with the Tlooding and subsequent drainage of many watersheds on Isle Royale, a process that would likely result in the release of methylated mercury into adjacent environments (St. Louis 2004). While there is no doubt that beaver are a valuable component of ecosystem health, the purpose of mentioning this possibility is to highlight the deeply pervasive inTluence that top predators have on ecosystems (Terborgh & Estes 2010). A discontinuity in predation is likely to have unanticipated negative effects on ecosystem health. A temporal gap in predation would likely result in long-­‐lasting effects on Isle Royale’s forest dynamics and herbivory. Throughout most of the forests on Isle Royale where balsam Tir occurs, those trees are either old canopy trees, established about a century ago before the arrival of moose, or are shorter than ~1.5 meters (Brandner et al. 1990; McLaren and Janke 1996). The short Tirs are a dominant forage for moose during winter and are kept short by herbivory. Canopy Tirs are the only source of seeds to regenerate the species. Because of their age, the canopy trees have been rapidly dying and will soon be functionally absent (Vucetich and Peterson 2007, Frelich et al. 2012). However, between 2005 and 2011 the moose population experienced the most protracted period of low abundance ever observed. That low abundance was, in part, attributable to predation. During that period, the shorter Tir trees began growing at an unprecedented rate. By 2013, many were approaching a height (>3 m) where they will both begin to produce seeds and escape into the canopy. However, a rapid increase in moose abundance caused by low predation (like that observed in 2012 and 2013) could easily prevent that escape. Balsam Tir growing into the canopy is a basic process for any boreal forest comprised of balsam Tir. Even a brief discontinuity in predation’s inTluence at this time could prevent a process that hasn’t occurred in the past century 20. Restoration
Because Tir is a dominant winter forage for moose, and because a discontinuity in predation could cause a long-­‐term decline in balsam Tir that is not easily reversed; the result could be a long-­‐term decline in moose abundance, which could impair the viability of a reintroduced wolf population. For those reasons, it cannot be taken for granted that reintroduction would result in ecological restoration. Moreover, reintroduction has no chance of resulting in genetic restoration. Genetic restoration involves concerns for neutral, detrimental and adaptive genetic variation (Seal 1995, Hedrick 2005). While genetic rescue is important for removing detrimental variation, the Isle Royale wolf population may also possess genetic variants that are adaptive to living on Isle Royale. This possibility is supported by the documented rapid genetic change for many different traits in various breeds of Canis lupus familiaris (Boyko et al., 2010), increasing evidence that rapid evolution is not uncommon (e.g., Schoener 2011), and evidence that such changes may be most difTicult to detect, paradoxically, when the ecological consequences of such changes are most important (Ellner et al. 2011). Such circumstances call for the application of the precautionary principle. Moreover, conserving those important genetic variants would require conserving the existing population and cannot be accomplished through reintroduction.
Aesthetics, Education, and Public Narrative 20 During the late 1980s and early 1990s, balsam fir in large por0ons of Isle Royale nearly escaped from moose herbivory but were prevented by a period of severe herbivory. During that 0me, moose broke the ver0cal stems (1-­‐3 cm in diameter) of many fir trees that had nearly grown beyond the reach of moose. Severe herbivory during that period also caused many other fir trees to die back in height. This severe herbivory was caused by very high moose abundance, brought on by low wolf preda0on during the late 1980s and early 1990s, which was caused, in part, by inbreeding and a wolf disease brought by humans.
24
Aesthetics and public narrative are also valuable considerations. The wolves and moose of Isle Royale are certainly associated with a public narrative that has educational and aesthetic value. In this context, some are liable to believe that reintroduction would have greater value. For example, there might be an object lesson associated with public reTlection on the sadness of extinction, or the realization that genetic decline in small populations is a real extinction threat. Refraining from genetic rescue could possibly provide the opportunity to tell a remarkable story of how Isle Royale wolves come back, temporarily, from the brink of extinction. Others, however, are liable to believe genetic rescue would provide a more valuable public narrative. For example, genetic rescue on Isle Royale would highlight the value of seeing wilderness areas and parks as places where ecosystem health is of critical importance, even if that health requires human assistance. Genetic rescue would also be an opportunity to celebrate a hopeful narrative, one centered on the human capacity to conserve ecosystem health and the willingness to express care for nature.
Reintroduction and genetic rescue might also form the basis for other narratives, with different educational and aesthetic value. The examples given here are only intended to be of heuristic value. They are important for suggesting how untenable it would be to conclude that reintroduction is more or less valuable than genetic rescue, with respect to the educational and aesthetics value of public narrative.
is beyond the scope of this paper. Nevertheless, a few considerations seem useful. For example, it seems straightforward to attempt a subsequent genetic rescue if the immigrant wolves from a prior attempt at genetic rescue died before reproducing. Because wolves die at a relatively h i g h r a t e u n d e r t h e b e s t o f e c o l o g i c a l circumstances, one should be prepared for that circumstance.
Similarly, it would be important to develop demographic or genetic criteria that would trigger the need for a subsequent genetic rescue. If the history of the Isle Royale wolf population is any indicator, then genetic rescue (which might consist of adding as few as one or two wolves from the mainland) might need to be implemented perhaps, once every 20 to 40 years21. However, the genetic rescue of Florida panthers in Everglades National Park appears to have been very successful (Johnson et al. 2010), and there has been no d i s c u s s i o n o v e r t h e n e e d f o r f u r t h e r translocations. If the wolf population is characterized by detrimental genes, then the infusion of new genes (the result from genetic rescue) might provide an opportunity for those detrimental genes to be reduced in frequency or eliminated. However, it is possible that the population would go extinct in spite of genetic rescue. At that point, reintroduction could be implemented. Should that possibility be realized, documenting the details of such an outcome would be quite valuable to conservation science. Conclusion
Planning for genetic rescue Before implementing genetic rescue, there would be value in developing criteria for determining what would trigger the need for a subsequent genetic rescue (see e.g., Hedrick and Fredrickson 2010). The details of those criteria would be mostly technical in nature and their development If a thing is valued, it seems straightforward to conserve it, rather than let it be lost with the expectation that it can later be restored. In this general sense, conservation seems preferable to ecological restoration (see also Moore and Moore 2013). Moreover, in this case, genetic restoration is almost certainly not possible without genetic 21 For the first 45 years of its existence, the Isle Royale wolf popula0on likely went without any immigrants that subsequently reproduced. It has been about 15 years since the arrival of the 1997 immigrant. The gene0c benefit of that gene0c rescue may have been limited, because it involved only a single immigrant aker a long period of inbreeding.
25
rescue. In some cases, an extenuating circumstance might suggest that ecological restoration is preferable to conservation. H o w e v e r , w e a r e u n a w a r e o f a n y s u c h circumstance for the Isle Royale case. If we have neglected any such considerations, we hope this essay simulates discourse that would speak to those considerations. Genetic rescue is not only likely to overcome any detrimental effects from inbreeding that have built up in the population, but could potentially bring in new variation while allowing any present adaptive variation to remain. To m a i n t a i n p r e d a t i o n o n I s l e R o y a l e , t h e introduction of new wolves for genetic rescue is 26
the easiest, quickest, and most reliable approach. This is certainly suggested by previous experience with the successful genetic rescue, including Florida panthers (Johnson et al. 2010) and Scandinavian wolves (Vila et al. 2003). Because reintroduction is less likely to result in ecological restoration and very unlikely to result in genetic restoration, genetic rescue also is the course of action that is consistent with the precautionary principle. 4. MOOSE AND CLIMATE CHANGE
The text below (in grey, sans serif font) was authored by Ted Gostomski of the National Park Service. This essay was originally printed in 2013 in the George Wright Forum (www.georgewright.org/
301gostomski.pdf). This essay raises several concerns about the analysis presented in chapters 1 and 2 of this document. The most important concerns deal with climate change. Our response to this essay was printed in the same issue of the George Wright Forum and appears on page 31 of this document (see also (www.georgewright.org/301vucetich.pdf).
Are Isle Royale Wolves Too Big to Fail? A Response to Vuce:ch et al.
By Ted Gostomski
Vuce0ch et al. (2012) have proposed reintroducing wolves to Isle Royale Na0onal Park (Lake Superior, Michigan, USA), arguing that unnatural causes (humans) have brought the island wolf popula0on to the brink of ex0nc0on. They argue that protec0ng Isle Royale’s ecological integrity—a fundamental tenet of Na0onal Park Service (NPS) policy—refutes almost any argument to be made against reintroduc0on. However, in making their case, Vuce0ch and his colleagues lek out some important facts about the history of wolves on Isle Royale, and I believe they exaggerate the wolf’s role in the significance of the island as a na0onal park and as a federally designated wilderness area. Also, they feel that the “ques0on at stake” in considering reintroduc0on is whether or not to allow a long-­‐term research project to end (p. 134). That is a far different line of reasoning than the welfare of wolves and moose, ecological integrity, wilderness values, or how visitors form connec0ons with the island. That line of reasoning raises a ques0on about Isle Royale wolves similar to one asked about banks in the United States during the economic recession: “Are they too big to fail?”
Vuce0ch and his co-­‐authors invite broader discussion on the topic of reintroduc0on, and I hope others will take up that offer, but I think the discussion should be based on all the available informa0on. I present here some of what I think was lek out of Vuce0ch et al.’s ar0cle, but which I feel is very relevant to any considera0on of wolf reintroduc0on on Isle Royale.
A historical perspec:ve
The discussion in the 1931 Congressional Record accompanying the legisla0on that created Isle Royale Na0onal Park includes a leqer by NPS Director Horace Albright that speaks of the island’s “exquisite, rugged beauty,” the 2,000 moose and 400 woodland caribou that “in itself will present an unusually fine wild-­‐life spectacle,” and the wealth of flora. He speculates that the good fishing will be a popular aqrac0on for visitors, and he comments on the interes0ng archaeological features to be found on the island. He concludes by saying it is “evident that from a scenic, recrea0onal, scien0fic, and educa0onal standpoint, here is presented one of the outstanding opportuni0es for establishment of a great island na0onal park, unique of its kind in the system, and measuring up to the high standards that have been prescribed for such establishment” (NPS 1998: Appendix E). The reader will note that Albright never men0ons wolves. He does not men0on wolves because they did not exist on Isle Royale when Congress authorized it as a na0onal park in 1931. They were not there when the Na0onal Park Service took over management of the island in 1936. They were not there on dedica0on day in 1940. Wolf tracks were first reported on the island in 1948, but their presence was not confirmed un0l 1951 (Peterson 1995). It is true, as Vuce0ch et al. point out, that one of the park’s current significance statements (those which “capture the essence of the park’s importance to the na0on’s 27
natural and cultural heritage”) acknowledges that Isle Royale is world renowned for the long-­‐term wolf–moose predator–prey study (NPS 1998). But neither the park’s emphasis statements (which “flow out of the park significance statements”) nor its purpose statements (which are “based on park legisla0on and legisla0ve history, other special designa0ons, and NPS policies”) men0on wolves (NPS 1998). Wolves and moose are important parts of Isle Royale to today’s visitor, but they are not the reason people advocated for the crea0on of the park, and they are not the only reason people come to visit the island today.
Wilderness values
Vuce0ch et al. contend that wolves (along with moose) are the icons of wilderness culture on Isle Royale and to lose them would “significantly wound Isle Royale’s wilderness character and important points of connec0on between people and Isle Royale” (p. 132). There are two problems with this statement. First, it suggests that Isle Royale is a wilderness because wolves and moose reside there. Wilderness is a subjec0ve character made manifest in different ways to different people. Baldwin (2011) points out that when the idea of crea0ng a na0onal park on Isle Royale was first catching on in the 1920s (about 20 years before wolves first arrived on the island), “wilderness was a much less exact word—a word ripe for interpreta0on, a word that, through the efforts of many individuals, became synonymous with Isle Royale.” In other words, it was the place itself that defined wilderness. Given that these discussions occurred at least 40 years before the passing of the Wilderness Act (1964), it is fair to say (and it has been said) that Isle Royale helped to define what wilderness is, and it did so before wolves arrived. Wolves are part of Isle Royale’s wilderness character now, but they are rela0ve newcomers.
The second problem with this statement is that it suggests wolves and moose are the only points of connec0on for people to make with the island. Any park interpreter will tell you that people make connec0ons with a place by iden0fying with the intangible values (solitude, isola0on) as well as the tangible resources (wolves, 28
moose). People see in Isle Royale and in wilderness something beyond themselves and even beyond 0me. That is to say, Isle Royale and its wilderness character transcend the presence of wolves and moose. True, they are prominent members of the island community, but in their absence, will not people s0ll see in the island experience opportuni0es for challenge and adventure, for connec0on with higher ideals and with those things closest to their hearts? Will people not s0ll revel in the sound of loon calls at night or the sight of the northern lights, or the sense of distance and isola0on? People connect with Isle Royale for many reasons. Wolves and moose are not the en0rety of the island’s worth.
The authors an0cipate cri0cism of their using the term “ecosystem health” to jus0fy reintroducing wolves because they feel it could be seen as a veiled aqempt to preserve “vigneqes of a primi0ve America” or as a contradic0on to NPS management policies, which allow for “natural processes” to be a guiding principle in resource management. In their aqempt to preemp0vely refute this argument, they affirm their belief that primi0ve America is gone and “natural process” is an outdated concept. “The weakness of the detractor’s posi0on,” they write, “arises from the concept of natural being fraught with debilita0ng dilemmas that have remained intractable despite being considered for more than two millennia. The concept of ‘natural’ is increasingly difficult to make sense of because of human impact on the planet” (p. 133). It is true that it is difficult to adequately define “natural,” but if that word is difficult, “wilderness” is significantly more so. It too has been extensively debated and with far more polarizing results (Cole and Yung 2010; Baldwin 2011). Wilderness is a human construct that, unlike “natural,” has not changed because of human impact on the planet; rather it was created by human impact on the planet. This makes the idea of wolves and moose being the epitome of Isle Royale’s wilderness soul all the more tenuous. If wolves and moose “make” a place wilderness, do we give such a 0tle to all of northern Minnesota, Wisconsin, and upper Michigan, where wolves are thriving and moose, though less common, are also found? No, in part because there is a significant human presence in those areas that refutes the assignment of that word. So if wolves in northern Minnesota, Wisconsin, and Michigan do not make those places wilderness, what elevates Isle Royale to the status of a wilderness? I submit that Isle Royale’s isola0on and the lack of a permanent human presence are perhaps the two leading factors, but that there are a host of other tangible and intangible values that contribute to the island’s unique status.
Island ecology
Isle Royale, like any place, is a dynamic system, maybe more so because it is an island. Popula0ons of any plant or animal on an island lead a precarious existence because of the isola0on that comes with distance from a fresh gene pool. To say that the ex0nc0on of wolves on the island will “ s i g n i fi c a n t l y d i m i n i s h i t s e c o s y s t e m health” (because of the cascading effects of increasing moose severely impac0ng the vegeta0on) is only partly true. Just as our changing climate makes it a near certainty that wolves will never again be able to cross an ice bridge and recolonize the island on their own, it is also unlikely new moose will make the crossing. This is not because they physically cannot make the trip—
if they originally arrived by swimming (Peterson 1995), then they can probably do so again—but the arrival of new individuals is further hampered by a declining source popula0on in Minnesota and Canada (Dybas 2009; Lenarz et al. 2010; Lenarz 2012), so who will be lek to cross over? And what will they find when they come? Hoqer summers and milder winters will challenge the tolerance thresholds of moose, while a predicted shik in the forest types of the north may make it difficult to find appropriate food. Will a future Isle Royale be able to sustain a moose popula0on? If not, what happens then? Do we con0nue to bring wolves, then moose, then wolves again over to Isle Royale in order to sustain a research program or a par0cular vision of what the island is supposed to be?
Beyond naturalness
Vuce0ch et al. note that “ecosystem health may well be superseding non-­‐interven0on as a central value of wilderness” (p. 135). This is true. Cole and Yung (2010) advocate for more hands-­‐on management of parks and wilderness areas in the face of a changing climate, but they provide evidence for choosing interven0ons that will transform ecosystems into condi0ons more re si l i e n t to f u tu re cl i m ate s. D o es wo l f reintroduc0on create such condi0ons? More to the point, as moose—a species far more vulnerable than wolves to the changing climate—
con0nue to decline in Minnesota and Ontario and the southern limit of their range shiks north, it seems likely they will similarly decline on Isle Royale. If there comes a 0me when moose are gone, will there be a discussion about reintroducing them because wolves need a more reliable food source than beaver or snowshoe hare? This may be a ques0on for a much later 0me, but we are star0ng down that path now as we discuss the future of wolves. With wolves thriving in the Great Lakes states, it makes sense that they would con0nue to exist on Isle Royale if winter ice condi0ons facilitated their ability to cross over the lake. But as moose struggle at the southern edge of their range, it appears they will not be a common presence in the area that would likely be the source popula0on for immigra0on to the island (i.e., northern Minnesota and southern Ontario). So any future discussion of moose reintroduc0on hinges very heavily on managing for resilient ecosystems. NPS management policy, too, is moving toward considera0ons of adapta0on and ecosystem resilience. Two of the goals in the NPS Climate Change Response Strategy (NPS 2010) are to “incorporate climate change considera0ons and responses in all levels of NPS planning” (Goal 5), and “implement adapta0on strategies that promote ecosystem resilience and enhance restora0on, conserva0on, and preserva0on of park resources” (Goal 6). Part of adapta0on is “to reduce the risk of adverse outcomes by increasing the resilience of systems and suppor0ng the ability of natural systems and species to adapt to change.” If there comes a 0me when a decision will have to be made on the reintroduc0on of 29
moose, considera0on will have to be given to the poten0al for an adverse outcome.
Looking ahead
Isle Royale wolves are not too big to fail. But then we are not talking about failure; we are talking about change. This change may be human-­‐caused, but we cannot disregard the fact that humans have been coming to Isle Royale for thousands of years. Humans are a part of Isle Royale’s history. However one might feel about the cause of the wolf’s decline and ex0rpa0on from Isle Royale, there are hard truths to consider about their future viability on the island and that of moose as well. Pragma0c management in the face of a changing planet requires us to “ar0culate goals and objec0ves for parks and wilderness that are founded in a perspec0ve that views humans as part of, rather than apart from, nature” (Cole and Yung 2010).
Isle Royale wolves are an important part of the Isle Royale ecosystem, but they are only one of the most recent parts. Before wolves and moose, there were coyotes and caribou, and that rela0onship lasted for thousands of years before the arrival of human hunters put them on the path to their demise and ushered in the modern era of predator and prey (Cochrane 1996). Now we are faced with the imminent departure of wolves from the island scene, and it seems likely they will be followed by moose because many of the same factors influencing wolves are also at work on moose—climate change and its effects on habitat being the most prominent—and those factors are sure to be enhanced by the loss of a top predator.
I agree that wolves play a cri0cal role in balancing today’s island ecosystem, but ecosystems are dynamic, and change is a natural part of that dynamism. I think we need to look at the ques0on of reintroduc0on through a broader lens. We should acknowledge the iconic stature of the island’s wolves and moose and public interest in their welfare, but we should also be mindful of the island’s longer history, and we should cri0cally and objec0vely analyze the uncertainty of its clima0c future. The island’s wilderness character will survive as will the things that make it a na0onal park—scenic, recrea0onal, scien0fic, and 30
educa0onal values; solitude; and the rela0vely unbiased opera0on of ecological cycles on the landscape.
References
Baldwin, A.T. 2011. Becoming Wilderness: Nature, History, and the Making of Isle Royale Na@onal Park. Houghton, MI: Isle Royale and Keweenaw Parks Associa0on.
Cochrane, J.F. 1996. Woodland Caribou Restora@on at Isle Royale Na@onal Park: A Feasibility Study. Technical Report NPS/
NRISRO/NRTR/96-­‐03. Denver: NPS
Cole, D.N., and L. Yung. 2010. Beyond Naturalness: Rethinking Park and Wilderness Stewardship in an Era of Rapid Change. Washington, DC: Island Press.
Dybas, C.L. 2009. Minnesota’s moose: Ghosts of the northern forest? BioScience 59:824–828.
Lenarz, M.S. 2012. 2012 aerial moose survey. Minnesota Department of Natural Resources. Online at hqp://files.dnr.state.mn.us/
recrea0on/hun0ng/moose/
moose_survey_2012.pdf. Accessed 17 July 2012.
Lenarz, M.S., J. Fieberg, M.W. Schrage, and A.J. Edwards. 2010. Living on the edge: Viability of moose in northeastern Minnesota. Journal of Wildlife Management 74:1013-­‐1023.
NPS [Na0onal Park Service]. 1998. Final General Management Plan and Environmental Impact Statement, Isle Royale Na@onal Park, Michigan. Denver: NPS.
———. 2010. Na@onal Park Service Climate Change Response Strategy. Fort Collins, CO: Na0onal Park Service Climate Change Response Program.
Peterson, R.O. 1995. The Wolves of Isle Royale: A Broken Balance. Minocqua, WI: Willow Creek Press.
Vuce0ch, J.A., M.P. Nelson, and R.O. Peterson. 2 0 1 2 . S h o u l d I s l e R o y a l e w o l v e s b e reintroduced? A case study on wilderness management in a changing world. The George Wright Forum 29: 126–147.
Response to Gostomski (2013)
By Vucetich, Peterson, & Nelson
Vucetich et al. (2012) assesses some of the key values at stake in deciding whether to conserve wolves in Isle Royale National Park. Many points made in Gostomski (2013) misrepresent what we wrote. Some examples include: We did not, as Gostomski states, “afTirm [our] belief that primitive America is gone and ‘natural process’ is an outdated concept.” Rather, we highlighted the relevance of a substantial body of scholarship that explains the conceptual difTiculties associated with the concept ‘natural’ and how and why wilderness is an evolving concept. Nowhere do we suggest that wolves equal wilderness or vice versa, as Gostomski suggests. We did not assert or imply that the wolves of Isle Royale or the wolf-­‐moose project are “too big to fail” or that wolves and moose are “the entirety of the island’s worth.” Rather, we provided clear, objective evidence for the scientiTic and educational value of the Isle Royale wolf-­‐moose project. We also provided clear, objective evidence that wolves are important to the cultural and wilderness values of Isle Royale. Conversations about the relationship between humans and nature are challenging. It is unlikely that such conversations are advanced by hyperbole or misrepresentation. Gostomski suggests that perhaps wolves should not be reintroduced because climate change will make moose vulnerable to extinction, and cites the declining moose populations in Minnesota and Ontario as evidence for the concern. Moose population dynamics are certainly inTluenced by climate and climate change. But Gostomski’s explanation is undermined by the complexity of those effects. For example, the most important reason for moose decline in Ontario and Minnesota is likely an interaction between climate and parasites (especially brain worm) that moose acquire when they live in the presence of white-­‐
tailed deer. Because Isle Royale is deer-­‐free, Isle Royale may be among the last places at the southern limit of moose distribution where they survive. The complex inTluence of climate is also indicated by the fact that, after Tifty years of observation and analysis conducted by several groups of scholars, the inTluence of climate warming on the population dynamics of Isle Royale moose is equivocal at best (e.g., Vucetich and Peterson 2004, Wilmers et al. 2006). Soon we will publish an analysis suggesting advances in the timing of spring green-­‐up (an expected consequence of climate warming) favors population growth of Isle Royale moose. Also, since 2010 the moose population in northeastern Minnesota has declined by 52% (Minnesota DNR 2013); while during the same period of time the Isle Royale moose population has increased by approximately 70%. During winter 2013, the Isle Royale moose population exhibited both the highest occurrence of twins and second highest rate of recruitment ever observed in the population’s history. Gostomski also writes, “To say that the extinction of wolves on the island will ‘signiTicantly diminish its ecosystem health’ (because of the cascading effects of increasing moose severely impacting the vegetation) is only partly true.” We did not conjure that idea ourselves. The loss of top carnivores is considered by the community of conservation scholars one of the greatest causes of diminished ecosystem health (e.g., Estes et al. 2011). It would be a bold, precedent-­‐setting perspective, with far reaching implications, to suggest that a top predator should not be conserved because climate change might threaten the viability of their prey at some indeTinite time in the future. The consequences of climate change will be profound, but we will be poor at predicting many of its important consequences (e.g., Broecker 2010, Francis and Vavrus 2010, Taleb 2010). 31
5. ISLE ROYALE’S DYNAMIC FAUNA22
Since 1976 Isle Royale has been a federally-­‐
designated Wilderness, where the principle virtue that guides management is to minimize and mitigate human inTluences to the extent possible. From this perspective, Cochrane (2013)23 argues: (i) it is possible that wolves released from the Detroit Zoo Isle Royale wolves might have reproduced at some point in the early 1950s and contributed to the gene pool of the Isle Royale wolf population, (ii) moose may have been brought to Isle Royale by humans, and (iii) those human inTluences cast doubt on the value of conserving Isle Royale wolves. Here, we consider more carefully the legacy of the Detroit wolves and respond to the questions that Cochrane raises. Historical account
In Vucetich et al. (2012), we reported: “Three of the wolves that had been introduced by humans were killed or removed after they became a public nuisance and the other disappeared (Mech 1966).” Cochrane (2013) provides historical records, that had been unavailable to us, which suggest that two wolves were killed or removed and two disappeared. The two missing wolves (Jim and Queenie) survived for at least three or four weeks after being released in August 1952, afterward there were no subsequent sightings. If those wolves were to have contributed to the Isle Royale gene pool, they would have had to survive for at least eight months after their last sighting in order to breed and reproduce. Conrad Wirth, who had been the Director of the NPS at the time, stated in a letter shortly after the wolves’ disappearance that the NPS would continue to make careful observations in an effort to discover the fate of those wolves. That those would have survived long enough to reproduce without being seen is 22
questionable given those wolves had been raised in a zoo, fed by humans, accustomed to human presence, and concerted efforts had been made to Tind those wolves. Surviving would not have been enough. They would also have had to reproduce. For example, an entire pack of wolves came to Isle Royale on an ice bridge in 1967. After being attacked by resident, Isle Royale wolves, the pack returned to the mainland. Except one black wolf remained. It continued to live on Isle Royale for another Tive years. But it never reproduced. This example illustrates a simple idea: The social structure, territoriality, and mating system of wolves mean that reproduction in any particular wolf should not be taken for granted. Most wolves, under normal circumstances, die without ever reproducing. Ultimately, the most generous conclusion to draw from the historical record is, with signiTicant risk of being too generous: it is possible that these wolves survived and reproduced and it is possible that they did not.
Genetic considerations Genetic analyses cannot provide deTinitive evidence that either or both of these wolves reproduced, because it is possible that such reproduction occurred but subsequently the genes of those wolves did not persist in the population. This would occur, for example, if the Detroit wolves produced offspring that died without reproducing. (The social structure and mating system of wolves is such that a common fate of a wolf is to die without reproducing.) The most relevant evidence that genetic considerations can provide is to assess whether any portion of the gene pool for Isle Royale wolves, at particular This chapter was developed in collaboration with others and can be cited as: Vucetich, J.A., J. R. Adams, & R. O. Peterson.
2013. Isle Royale’s dynamic fauna. Chapter 5 In Vucetich, JA., R. O. Peterson, M. P. Nelson. 2013. The importance of
conserving the wolves of Isle Royale National Park. Michigan Technological University., 50 pages
23
Cochrane (2013) is an unpublished manuscript.
32
points in the history of the Isle Royale population, trace to the Detroit wolves. To use technical jargon, one can ask whether the Isle Royale population has any ancestry to the Detroit wolves.
By the early 1980s, the earliest period of time for which genetic information is available, D N A o n t h e Y c h r o m o s o m e a n d i n t h e mitochondria of Isle Royale wolves was quite unlike the DNA at those sites which characterizes mainland Michigan wolves (J. Adams & L. Waites, pers. comm.). Because mtDNA is inherited only from mothers and DNA on the Y-­‐chromosome is inherited only from fathers, one can conclude that the female side of the Isle Royale gene pool was not inherited from Queenie and male side was not inherited from Jim.
By 2010, 100% of the population’s ancestry was attributable to three wolves. One wolf, an immigrant from Canada, represented >60% of the ancestry. For this reason, Detroit wolves cannot account for any portion of the gene pool. The other <40% of ancestry was traceable to two Isle Royale wolves that were born in the mid 1990s (F99 and F67, Adams et al. 2011). Even if the Detroit wolves did reproduce, it is very unlikely, due to the processes of genetic drift and recombination, that more than half the ancestry of those wolves could be traced to the Detroit zoo. If so, the greatest imaginable (this requires considerable imagination) contribution of the Detroit wolves would be less than about 20% (i.e., half of the ancestry attributable to F99 and F67). An important distinction
These genetic considerations give occasion to recognize an important distinction. In particular, one might be concerned about the possibility that (i) humans inTluenced the gene pool of Isle Royale when the Detroit wolves were released, or one might be concerned about the possibility that (ii) Isle Royale has a wolf population today because humans released the Detroit wolves. If case (i) were true, the concern might be that humans had inappropriately inTluenced the gene pool of Isle Royale wolves. It is difTicult to think that an appropriate response to that concern would be removal of the population (or counting it good to see the population go extinct). Instead, the most thorough mitigation for that concern would be, it seems, to purge Detroit genes from the Isle Royale population. Because genes from Detroit wolves now appear to be absent (and were very plausibly never present), this is exactly the outcome that has come to be. Case (ii) seems quite unlikely. First, wolves seem to have established a population on Isle Royale by approximately 1948. Second, if they had not done so in 1948, they would likely have done so in 1967 when pack of wolves crossed an ice bridge to Isle Royale24 . Historical human inCluences
The Detroit wolves were introduced 24 years prior to Isle Royale being dedicated as a federally-­‐
designated Wilderness. Humans had quite a few human inTluences on Isle Royale prior to its being designated a wilderness. Many of those historic, pre-­‐wilderness inTluences are celebrated and preserved, e.g., shipwrecks that litter the lake bottom, mining, and over-­‐exploitation of Tish populations. Whatever one may think about the history of extractive use in some areas that are now designated as wilderness, the release of Detroit wolves to Isle Royale cannot be construed as some shamefully exploitive endeavor. It was conducted on the advice of people who we now consider conservation heroes and architects of wilderness philosophy (i.e., A. Murie, A. Leopold, S. Olson). They had developed that advice out of concern for the detrimental impact of moose on the ecological integrity of Isle Royale. A widely appreciated weakness of wilderness philosophy is its tendency to disvalue historic human inTluences in areas that are subsequently declared wilderness (see e.g., Cronon 2008). That dis-­‐valuation is troubling because it 24
Those wolves left after being attacked by resident, Isle Royale wolves, but likely would have had the island not been
colonized by that time. Except one black wolf remained. It continued to live on Isle Royale for another five year. But it never
reproduced.
33
transmogriTies the genuine wisdom of wilderness philosophy into something misanthropic. Moose Origins
Cochrane (2013) also wonders about the possibility that humans introduced moose. In this context, it is relevant to recognize that swimming across twenty or more miles of frigid Lake Superior water seems a superhuman feat. It is. But, moose frequently disperse through tens of miles of cold, ocean waters of British Columbia and Scandinavia (references). [Rolf, can you add the text about direct observations of moose swimming in Lake Superior.] That moose colonized Isle Royale on their own is abundantly plausible. The only evidence Cochrane presents for humans having introduced moose to Isle Royale is that he heard someone say so in the parking lot of a gas station. [Rolf, can you describe your search of the MN newspapers, where you failed to Pind any evidence for humans having introduced moose.] So, what is the point of wondering about how moose arrived, given the evidence. We do not know. Cochrane implies that it should affect how we value Isle Royale moose and that it should affect management decisions about Isle Royale wolves. How should it inTluence valuation and management? We have no idea and Cochrane (2013) never says. Logical fallacies
Raising the question “What if humans are the reason why wolves and moose exist on Isle Royale?” seems to call for evaluating the likelihood of that proposition and how the likelihood of that proposition should inTluence management decisions. Cochrane (2013) does not even outline a proposal for how those prospects might inTluence management. Instead he only implies that raising the question will lead to the conclusion that conserving wolf predation on Isle Royale would be inappropriate. 25
Humans might have introduced deer mice and red squirrels to Isle Royale several thousand years ago, when they brought them over on boats. Isle Royale’s pine martens, which are purported to be a distinct subspecies, feed on mice and squirrels. If so, then humans played a role in creating that subspecies. Doesn’t that raise questions about the value and management of Isle Royale’s pine martens? The conclusion implied by that string of comments is absurd, but also perfectly analogous to the rhetorical strategy presented in Cochrane (2013).
Raising questions designed to cast doubt, without even attempting to explore the implications of those questions is a rhetorical strategy identiTied in critical thinking textbooks as a kind of logical fallacy known as a red herring (Copi and Cohen 2001). Raising propositions that require evaluation, and then implying what such an evaluation would conclude without conducting that evaluation is a second kind of logical fallacy known as begging the question (Copi and Cohen 2001). These logical fallacies sometimes serve as good literary devices and sometimes even have pedagogical value, but they are not good practice in scholarship or policy evaluation. Vignettes from primitive America
Because of its rhetorical strategy, responding to Cochrane (2013) requires us to infer what the genuine concern might be. An implied, but veiled concern, raised in Cochrane (2013) and Gostomski (2013) is that conserving Isle Royale wolves is an act of nostalgia25 , an attempt to preserve a vignette of nature’s past in a manner that contradict the wisdom of valuing nature’s dynamic ways. Conserving predation is not an act of nostalgia. It is a global conservation priority (Estes et al. 2011). By whatever means moose arrived to Isle Royale, they are there and will be for the foreseeable future. The integrity of ecosystems inhabited by large ungulates, such as moose, depends critically on the presence of There is something deeply ironic about this concern because the preservation of wilderness is fundamentally an act of
nostalgia, at least according to some well-respected scholars (Leopold 1949). The exception to that perspective would be
when wilderness is valued as a scientific benchmark for better understanding the health of other ecosystems.
34
predation. FulTilling the mission of NPS requires the preservation of ecosystem integrity of national parks. Indeed, extinction can be a natural process, especially on small islands. However, it is foolish to portray the Isle Royale case as some kind of dilemma in honoring two natural processes, extinction and predation. First, it is a stretch to conclude that humans have not signiTicantly affected Isle Royale wolves. Human-­‐introduced disease and anthropogenic climate warming have likely contributed in a signiTicant way to the impaired condition of Isle Royale wolves (Chapter 1). Second, we have driven top predators to extinction from most of the places where they once lived. As a result, we have turned Isle Royale into a globally unique ecosystem for: (i) being comprised of a top predator, large herbivore, and forest, where none of those trophic levels are hunted or logged by humans, (ii) being accessible to citizens who value the opportunity to witness that natural beauty, and (iii) being well studied for the purpose of understanding the contributions of top predators to ecosystem integrity. Conserving predation on Isle Royale is not an act of nostalgia, it is to fulTill the mission of the NPS, which is to preserve natural resources, unimpaired, for the enjoyment, education, and inspiration of this and future generations.
35
6. OPENING PANDORA’S BOX?
Introduction
The prospect of conserving Isle Royale wolves raises a critical concern about the goal of conservation in a world exposed to seemingly endless forms of human-­‐caused global change – climate destabilization, widespread carnivore extinctions, spread of exotic species and novel diseases, altered biogeochemical cycles, rampant habitat destruction, to name a few. The concern is that global change will result in many inevitable degradations to ecosystem health and other losses in the natural world. Glaciers will be lost from Glacier National Park. Sequoia trees will be lost from Sequoia National Park. Rising oceans will devastate or consume Everglades National Park. The concern with conserving Isle Royale wolves goes something like this: Doing so would set a quixotic precedent that every inevitable change should be resisted, and in vain. If Isle Royale wolves merit conservation, then so too would a myriad other cases where global change has or is expected to cause harm. Global change and its effects are inevitable and resistance is futile. In a world where resources for conservation are limited, it is especially fool-­‐
hearty to waste human and Pinancial resources on even one such case. Sad as it may be – and we should prepare for greater sadness to come – Isle Royale wolves should be allowed to go extinct. Otherwise, the precedent that would be set by conserving Isle Royale wolves would be to open a kind of Pandora’s box. Concerns of that nature are tragically misplaced. We peeked into Pandora’s box each time we exposed another ecosystem to an exotic species or novel disease. We stared into the bottom of Pandora’s box each time we let another population of carnivores go extinct. We unleashed another scourge from Pandora’s box each time we failed to enact public policies to further limit air and water pollution. We opened Pandora’s box and tossed the lid away when we allowed atmospheric CO2 to 36
hit 400ppm. It is a disastrous mistake to confuse opening Pandora’s Box with realizing the need to deal with Pandora’s Box having been opened.
Preserving ecosystem health in a world of global change
For a century the NPS mission has been the preservation of ecosystem health. During its early history, preservation seemed (and in many ways was) best accomplished by not intervening with natural processes. By the second half of the 20th century, the NPS grew to realize that preserving e c o s y s t e m h e a l t h w o u l d r e q u i r e a c t i v e conservation in some circumstances to mitigate humans affects. This shift in attitude resulted, for example, in controlled burns in Sequoia National Park to mitigate the detrimental effects of Tire suppression, and the reintroduction of wolves to Yellowstone National Park. Today the detrimental effects of global change are more dire than ever before and expected to get worse. The NPS could concede its distinctive mission – America’s best idea – and acquiesce without resistance to the detrimental effects of global change, because global change is inevitable. Alternatively, the National Park Service could resolve more than ever before to carry forward with its mission of preserving ecosystem health to the extent possible. FulTilling its mission under these conditions will however, require new strategies. And one of those strategies will necessarily be to rely increasingly on the wise application of active conservation. The need to do so is undesirable, but that situation is the terribly unfortunate result of global change, a world that we have made for ourselves. The Revisiting Leopold Report
There is no established, time-­‐tested management philosophy to guide the NPS in facing the unprecedented global change that we now experience. However, the Revisiting Leopold Report (2012) is an important exploration of such a philosophy. That report was authored by a twelve member panel at the request of the Director of the NPS. The panel represented expertise in the challenges of global change, the mission of the NPS, and its policies. While the importance of this document for guiding future management will not be known for some time, there is clear value in considering the Isle Royale case in light of the ideas conveyed in that report.
In particular, the report highlights that “the National Park System contains many of the land-­‐ and seascapes most capable of sustaining ecological integrity...” and concludes that “the NPS should also lead the way in establishing … benchmarks of ecological integrity…” Those statements are germane to the Isle Royale case, because this National Park is a truly distinctive benchmark of ecological integrity. Isle Royale serves as this bench mark because it is both: (i) one of the few places on the planet where a top predator, large herbivore, and forest ecosystem all exist without any of those trophic levels being harvested by humans; and (ii) those trophic interactions are the subject of the longest study of any predator-­‐prey system in the world. The report goes further to say that detrimental impacts of global change to NPS resources should be resisted (emphasis added): “the overarching goal… should be to steward NPS resources for continuous change that is not yet fully understood, in order to preserve ecological integrity… and form the core of a national conservation land-­‐ and seascape. … This vision emphasizes the role of parks as spatially Pixed, largely intact areas embedded in a matrix of adjacent lands and waters where use will change dynamically over time.” With this goal, the report explicitly indicates “the necessity that management may involve active manipulation of the plant and animal communities, or protection from modiPication or external inPluences.” The report also provides some consideration for prioritizing efforts to preserve ecological integrity:
“Confronted with continuous and dynamic change and the goal of preserving ecological integrity, NPS management strategies must be expanded to encompass… prioritizing the protection of habitats that may serve as climate refugia, ensuring the maintenance of critical migration and dispersal corridors, and strengthening the resilience of park ecosystems.”
Again, this statement is germane to the Isle Royale case because this national park will likely become a climate refuge for moose in the contiguous United States if moose are unable to persist in environments characterized by both warmer climates and parasites carried by white-­‐tailed deer that are expanding northward with climate warming (see Vucetich et al. 2013). That statement is also germane because climate warming is the cause of wolves’ impaired ability to disperse from the mainland to Isle Royale National Park.
The report reafTirms the need for the NPS to “provide transformative visitor experiences” and states that “the public must [also] be made aware of the challenges facing the National Park System and urged and empowered to take action to preserve and protect these resources as part of their enduring responsibility as citizens.” The wolves of Isle Royale have long been key to providing transformative experiences for many visitors to Isle Royale National Park (see e.g. the appendix of Section 2). Moreover, Isle Royale National Park is a truly unique ecosystem for simultaneously being inhabited by a top predator; for being intact in the sense that humans hunt neither wolves nor moose, nor log its forests; and for being accessible for citizens to witness. The relevance of this unique condition is conveyed, where the report states, “speciPic tactics include improving [and preserving] the representation of unique ecosystem types within the National Park System, prioritizing the protection of habitats that may serve as climate refugia,… and strengthening the resilience of park ecosystems.”
37
Precautionary principle
The Revisiting Leopold report also emphasizes the precautionary principle: “this policy should formally embrace the need to manage for change, the precautionary principle, and to the maximum extent possible, maintain or increase current restrictions on impairment of park resources.” In that passage “manage for change” refers to managing for the preservation of ecosystem integrity in the face of global change. The report also says of the precautionary principle that its “standard is conservative in allowing actions and activities that may heighten impairment of park resources and consistent in avoiding actions and activities that may irreversibly impact park resources and systems.” The precautionary principle is relevant to the Isle Royale case. One concern is that ignorant desire to improve nature has motivated many actions in human history that created considerable unintended harm. That concern raises the question, Is genetic rescue another one of those misguided desires – a case of conservation hubris?. The precautionary principle’s antidote to concerns like this is to refrain from action. This concern seems to suggest that non-­‐intervention is the safest course of action – the action associated with least risk of causing harm.
This concern rises from a misapplication of the precautionary principle. Genetic rescue is, by far, the option associated with the least risk of causing harm (see Section 3, Conservation is Preferable to Restoration). In a world of global change, the precautionary principle will more frequently call for the wise application of active conservation rather than non-­‐intervention.
Evolving methods, enduring mission
The Revisiting Leopold report was explicit in its interest to neither reafTirm or reject speciTic elements of the Leopold Report (1964). Rather, it focused on developing an independent assessment of topics that had been covered in the Leopold Report. Nevertheless, the Revisiting Leopold report conspicuously quoted some passages from the Leopold Report:
38
“ ’A national park should present a vignette of primitive America.’ The authors also described implications of this goal as ‘not done easily nor can it be done completely.’ The report was adamant: ‘Yet, if the goal cannot be fully achieved it can be approached…This in our opinion should be the objective of every national park and monument.’ ”
The idea of preserving “vignettes of primitive America” may have been intended to anchor a new management philosophy to the original mission of the NPS. However, it is a poor phrase for conveying a sense that is contrary to scientiTic knowledge about how nature works, as well as being culturally offensive to the history of Native Americans. The Revisiting Leopold Report calls for preserving “bench marks of ecological integrity.” That call honors science, culture and is intimately tied to the NPS original mission. The NPS mission to preserve natural resources dates back to the 19th century. Science clearly indicates how it is critical to preserve ecological changes and dynamic processes that enhance ecological integrity. Science is just as clear in providing reasons to resist the detrimental changes and processes associated with human-­‐
caused global change. Ecological integrity embraces the Tirst kind of change, not the second. The NPS mission endures. The Revisiting Leopold report does no more than to communicate an inescapable reality: FulTilling that mission in a world of human-­‐caused global change is more important than ever, but fulTilling that mission will require new strategies, including increased application of wisely administered active conservation. The revisiting Leopold Report provides a clear perspective from which to see that conserving Isle Royale wolves with genetic rescue is not a radical or anomalous interpretation of NPS policy or its mission. Just the opposite. Through the lens of the Revisiting Leopold Report, with its emphasis on using the precautionary principle to preserve ecosystem integrity, genetic rescue is the only reasonable response to the Isle Royale case. New challenges, enduring mission
Every new era of management brings with it new uncertainties and new challenges. In particular, knowing what elements of ecosystem health to preserve and what element to let slip. Presumably this would be judged from some basis of value, feasibility, and the precautionary principle. If so, predation on Isle Royale is a relatively easy case. Its value is deeply signiTicant, the actions required for its conservation are modest, and the precautionary principle unequivocally supports its conservation. Other management challenges are just around the corner, and they will almost certainly be more difTicult to evaluate than this Isle Royale case. Failing to embrace conservation on this occasion would bode poorly for the NPS’s resolve to preserve ecosystem health in the face of human-­‐caused global change. Shifts in management philosophy are not without risks. Mistakes will be made. The history of management demonstrates that mistakes are unavoidable. But the risks and mistakes of clutching to old strategies are dire in comparison to the risks of developing new strategies that can cope with the onslaught of human-­‐caused global change.
The Everglades Restoration Project is an occasion for reTlection. It is the most expensive and involved restoration project in the history of humanity, and it should be completed within Tifty years or so of the ocean consuming all that we will have restored there. How can that effort, expense, and use of human creativity be justiTied? It is justiTied because it is our obligation, and the mission of the NPS, to do whatever we can to stop, or slow, or reduce in any way harms to ecological integrity. Our children’s children may not forgive us for opening Pandora’s Box, but they will surely condemn our not making every effort to resist its detrimental effects.
39
REFERENCES
Adams, J.R., L.M. Vucetich, P.W. Hedrick, R.O. Peterson, and J.A. Vucetich. 2011. Genomic sweep and potential genetic rescue during limiting environmental conditions in an isolated wolf population. Proceedings of the Royal Society, London B (doi:10.1098/rspb.
2011.0261).
Addison, E.M., R.F. McLaughlin, and J.D. Broadfoot. 1994. Growth of moose calves infested and uninfested with winter ticks. Canadian Journal of Zoology 72, 1469-­‐1476. Allen, D.L. 1979. Wolves of Minong: Their Vital Role in a Wild Community. Boston: Houghton MifTlin.
Allendorf, F. and G. Luikart. 2003. Conservation and the Genetics of Populations. Blackwell. Arcese, P. and A.R.E. Sinclair. 1997. The role of protected areas as ecological baselines. J. Wildlife Management 61: 587-­‐602.
Austin, J. A., and S. M. Colman (2007), Lake Superior summer water temperatures are increasing more rapidly than regional air temperatures: A positive ice-­‐
albedo feedback, Geophys. Res. Lett., 34, L06604, doi:
10.1029/2006GL029021. Beisner, B.E., D.T. Haydon, and K. Cuddington. 2003. Alternative stable states in ecology. Frontiers in Ecology and the Environment 1, 376–382.
Berzon, J.L., Dueland, R., 1979. Cauda equina syndrome: pathophysiology and report of seven cases. Journal of the American Animal Hospital Association 15, 635–643.
Broecker, WS. 2010. The Great Ocean Conveyor, Discovering the Trigger for Abrupt Climate Change. Princeton University Press.
Bump, J.K., R.O. Peterson, and J.A. Vucetich. 2009. Wolves modulate soil nutrient heterogeneity and foliar nitrogen by conTiguring the distribution of ungulate carcasses. Ecology 90, 3159 –3167.
Callicott, J.B. and M.P. Nelson, eds. 1998. The Great New Wilderness Debate. Athens, GA: The University of Georgia Press.
Case, D.J. and D. R. McCullough. 1987. The white-­‐tailed deer of North Manitou Island. Hilgardia 55, 1-­‐57.
Caughley, G. 1994. Directions in conservation biology. Journal of Animal Ecology 63: 215-­‐244.
Clark, C.P. 1995. Archaeological Survey and testing at Isle Royal National Park, 1987-­‐1990 Seasons. Lincoln, Nebraska, Midwest Archaeological Center, US DOI, NPS).
Cochrane, J. F. 1996. Woodland caribou restoration at Isle Royale National Park. A feasibility study. US DOI, NPS Technical Report NPS/NRISRO/NRTR/96-­‐03.
Cole, D. N. and L. Yung. 2010. Beyond Naturalness: Rethinking Park and Wilderness Stewardship in an Era of Rapid Change. Washington, D.C.: Island Press.
Copi, I. and C. Cohen. 2001. Introduction to Logic. 11th Ed. Prentice-­‐Hall.
Beschta, B. L. and W. J. Ripple. 2009. Large predators and trophic cascades in terrestrial ecosystems of the western United States. Biological Conservation 142, 2401-­‐2414.
Cronon, W. 2008. The Riddle of the Apostle Islands: How Do You Manage a Wilderness Full of Human Stories?” in The Wilderness Debate Rages On: Continuing the Great New Wilderness Debate, Michael P. Nelson and J. Baird Callicott, eds. (Athens: University of Georgia Press, 2008), 634–635.
Boyko, A. R., P. Quignon, L. Li, J. J. Schoenebeck, J. D. Degenhardt, et al. 2010. A simple genetic architecture underlies morphological variation in dogs. PLoS Biology 8 (8), e1000451.
Dawson, C. P. and J. C. Hendee. 2008. Wilderness Management. Fulcrum.
Brandner, TA, R. O. Peterson, and K.L. Risenhoover. 1990. Balsam Tir on Isle Royale -­‐ effects of moose herbivory and population density. Ecology 71: 155-­‐164
40
DelGiudice, G.D., R.O. Peterson, and W.M. Samuels. 1997. Trends of winter nutritional restriction, ticks, and numbers of moose on Isle Royale. Journal of Wildlife Management 61, 895-­‐903.
Desjardins, J.R. 2000. Environmental Ethics: An Introduction to Environmental Philosophy. New York: Wadsworth Publishing.
Ellner, S. P., M. A. Geber, and N. G. Hairston, Jr. 2011. Does rapid evolution matter? Measuring the rate of contemporary evolution and its impacts on ecological dynamics. Ecology Letters 14: 603-­‐614. Estes, J.A., J. Terborgh, J.S. Brashares, et al (24 additional authors). 2011. Trophic Downgrading of Planet Earth. Science 333, 301-­‐306.
Flückiger, M.A., Damur Djuric, N., Hässig, M., Morgan, J.P., Steffen, F., 2006. A lumbosacral transitional vertebra in the dog predisposes to Cauda Equina syndrome. Veterinary Radiology & Ultrasound 47, 39–
44.
Francis, JA and SJ Vavrus. 2010. Evidence linking Arctic ampliTication to extreme weather in mid-­‐latitudes. Geophysical Research Letters 39, L06801, doi:
10.1029/2012GL051000
Frankham, R., J. D. Ballou, and D. A. Briscoe. 2007. Introduction to Conservation Genetics. Cambridge. Frelich, L. E., R. O. Peterson, M. Dovciak, P. B. Reich, J.A. Vucetich, and N. Eisenhauer. 2012. Trophic cascades, invasive species and body-­‐size hierarchies interactively modulate climate change responses of ecotonal temperate-­‐boreal forest. Phil Trans Royal Soc. B 367: 2955-­‐2961
Frisch, R. 2002. Female fertility and the body fat connection. University of Chicago Press. 208pp. Garner, D.L. and M.L. Wilton. 1993 The potential role of winter tick (Dermacentor albipictus) in the dynamics of south central Ontario moose population. Alces 29, 169-­‐173.
Gore M., M.P. Nelson, J.A. Vucetich, A. Smith, and M. Clark. 2011. Ethical justiTications for genetically rescuing an inbred population of wolves. Conservation Letters, in press.
Hampton, B. 1997. The Great American Wolf. New York: Macmillan.
Harmon, D. 2010. Review of Beyond Naturalness: Rethinking Park and Wilderness Stewardship in an Era of Rapid Change, edited by D. N. Cole and L. Yung, George Wright Forum 27, 255-­‐259.
Hedrick P. W. 2005. ‘Genetic restoration:’ a more comprehensive perspective than ‘genetic rescue’ Trend Ecol. & Evol. 20: 109-­‐109.
Hedrick, P.W. and S. T. Kalinowski. 2000. Inbreeding depression in conservation biology. Annual Review of Ecology and Systematics 31, 139-­‐162.
Hedrick, P.W., J. R. Adams, and J.A. Vucetich. 2011. Reevaluating and Broadening the DeTinition of Genetic Rescue. Conservation Biology 25:1069-­‐1070.
Hedrick, P. W. and R. Fredrickson 2010. Genetic rescue guidelines with examples from Mexican wolves and Florida panthers. Conservation Genetics 11:615–626.
Holling, C. S., and G. K. Meffe. 1996. On command-­‐and-­‐
control, and the pathology of natural resource management. Conservation Biology 10, 328-­‐337. Janzen, D. H. 1974. The deTlowering of Central America. Natural History 83, 48.
Johnson, W.E., Onorato, D.P., Roelke, M.E., Land, E.D., Cunningham, M., Belden, R.C., McBride, R., Jansen, D., Lotz, M., Shindle, D., Howard, J., Wildt, D.E., Penfold, L.M., Hostetler, J.A., Oli, M.K., O'Brien, S.J. 2010. Genetic Restoration of the Florida Panther. Science 329: 1641-­‐1645.
Karns, P.D. 1998. Population distribution, density, and trends. In Ecology and Management of the North American Moose. A. W. Franzmann and C. C. Schwartz, eds. Washington D.C.: Smithsonian Institution Press, 125-­‐141.
Kellert, S. R. 1990. Public attitudes and beliefs about the wolf and its restoration in Michigan. Madison, WI: HBRS, Inc.
Krefting, L.W. 1974. The ecology of the Isle Royale moose with special reference to the habitat. Agricultural Experiment Station Technical Bulletin No. 297, University of Minnesota, Minneapolis, Minn.
Lacy, R. C., and J. Ballou.1998. Effectiveness of selection In reducing The genetic Load in Populations of Peromyscus polionotus during generations of inbreeding. Evolution 52:900-­‐909.
Lacy, R. C., G. Alaks, and A. Walsh. 1996. Hierarchical Analysis of inbreeding depression in Peromyscus polionotus. Evolution 50:2187-­‐2200.
Lande R, S. Engen, and B.-­‐E. Sæther 2003. Stochastic Population Dynamics in Ecology and Conservation. Oxford.
41
Landres, P. 2010. Let it be: A hands-­‐off approach to preserving wildness in protected areas. In Beyond Naturalness. D.N. Cole and L. Yung, eds. Island Press, Washington DC, 88-­‐ 105. Lankester, M.W. and W.M. Samuel. 1997. Pests, parasites, and disease. In Ecology and Management of the North American Moose. A. W. Franzmann and C. C. Schwartz, eds. Washington D.C.: Smithsonian Institution Press, 479-­‐517.
Lappalainen, A. K., Salomaa, R., Junnila, J., Snellman, M., and Laitinen-­‐Vapaavuori, O. 2012. Alternative classiTication and screening protocol for transitional lumbosacral vertebra in German shepherd dogs. Acta Veterinaria Scandinavica 54:27.
Larsen, J.S., 1977. Lumbosacral transitional vertebrae in the dog. Journal of the American Veterinary Radiology Society 18, 76–79.
Lenarz, M. S., J. Fieberg, M. W. Schrage, and A. J. Edwards. 2010. Living on the Edge: Viability of Moose in Northeastern Minnesota. Journal of Wildlife Management 74, 1013–1023.
Lenarz, M. S., Nelson, M. E., Schrage, M. W. And Edwards, A. J. 2009. Temperature Mediated Moose Survival in Northeastern Minnesota. Journal of Wildlife Management 73, 503–510.
Leopold, A. 1949. A Sand County almanac and sketches here and there. Oxford University Press, New York, USA.
Lynch, M. 1988. Design and analysis of experiments on random drift and inbreeding depression. Genetics 120: 791-­‐807.
Marshall, K.N., N. T. Hobbs, and D. J. Cooper. 2013. Stream hydrology limits recovery of riparian ecosystems after wolf reintroduction. Proceedings of the Royal Society B 280: 1756 Article Number: 20122977 McLaren, B. E., and R. O. Peterson. 1994. Wolves, moose, and tree rings on Isle Royale. Science 266, 1555–1558.
McLaren, B.E. and R. A. Janke. 1996. Seedbed and canopy cover effects on balsam Tir seedling establishment in Isle Royale National Park. Can. J Forest Research 26: 782-­‐793
Mech, L.D. 1966. The Wolves of Isle Royale. U.S. National Park Service. Fauna Series No. 7.
42
Mech, L. D. and M. A. Cronin. 2009. Isle Royale study afTirms the ability of wolves to persist. Biological Conservation, 143: 535 -­‐ 536
Mech, L.D. 2013. Presentation delivered at The Disappearance of Isle Royale's Wolves: How Should We Respond, a public forum sponsored by the National Parks Conservation Association held on June 20th, 2013 in Minneapolis, MN. Audio available at URL: [accessed: 29 June 2013].
Minnesota Department of Natural Resources. 2013. Moose population drops dramatically; hunting season will not open. http://news.dnr.state.mn.us/2013 /
02/06/moose-­‐population-­‐drops-­‐dramatically-­‐hunting-­‐
season-­‐will-­‐not-­‐open/ (accessed 9 February 2013) Miller, B., B. Dugelby, D. Foreman, C. Martinez del Rio, R. Noss, M. Phillips, R. Reading, M.E. Soule, J. Terborgh, and L. Willcox. 2001. The importance of large carnivores to healthy ecosystems. Endangered Species UPDATE 18, 202-­‐210.
Moore K. D. and J. W. Moore. 2013. Ecological restoration and enabling behavior: a new
metaphorical lens? Conservation Letters 6:1–5.
Morgan, J.P., Bahr, A., Franti, C.E., Bailey, C.S., 1993. Lumbosacral transitional vertebrae as a predisposing cause of cauda equina syndrome in German shepherd dogs: 161 cases (1987–1990). Journal of the American Veterinary Medical Association 202, 1877–1882.
Morgan, J.P., Wind, A., Davidson, A.P., 1999. Bone dysplasias in the labrador retriever: a radiographic study. Journal of the American Animal Hospital Association 35, 332–340.
Morgan, J.P., Wind, A., Davidson, A.P., 2000. Lumbosacral disease. In: Morgan, J.P. (Ed.), Hereditary Bone and Joint Disease in the Dog. Schlütersche, Hannover, Germany, pp. 209–229.
Murie, A. 1934. The Moose of Isle Royale. Misc. Publ. Mus. Zool. Univ. Mich. No. 25.
Murray, D. L., Cox, E. W., Ballard, W. B., Whitlaw, H. A., Lenarz, M. S., Custer, T. W., Barnett, T. and Fuller, T. K. 2006 Pathogens, Nutritional DeTiciency, and Climate InTluences on a Declining Moose Population. Wildlife Monographs 166, 1–30.
National Research Council. 1991. Science and the National Parks. National Academy Press. Washington, D.C. Nelson, M. P. 2009a. Ecosystem Health. In Encyclopedia of Environmental Ethics and Philosophy. J.B. Callicott and R. Frodeman, eds. Farmington Hills, MI: Macmillan, 284-­‐286.
Nelson, M. P. 2009b. Wilderness. In Encyclopedia of Environmental Ethics and Philosophy. J.B. Callicott and R. Frodeman, eds. Farmington Hills, MI: Macmillan, 402-­‐405.
Nelson, M.P. and J.B. Callicott, eds. 2008. The Wilderness Debate Rages on: Continuing the Great New Wilderness Debate. Athens, GA: University of Georgia Press.
Nelson, M.P., R.O. Peterson, and J.A. Vucetich. 2008. The Isle Royale Wolf-­‐Moose Project, 50 Years of Challenge and Insight. George Wright Society 25, 98-­‐113. Nelson, M.P., J. A. Vucetich, R. O. Peterson, and L. M. Vucetich. 2011. The Isle Royale Wolf-­‐Moose Project (1958-­‐present) and the Wonder of Long-­‐Term Ecological Research. Endeavour 35, 30-­‐38.
Ondreka N, Amort K.H, Stock K.F, Tellhelm B, Klumpp S.W, Kramer M, and Schmidt M.J. 2013. Skeletal morphology and morphometry of the lumbosacral junction in German shepherd dogs and an evaluation of the possible genetic basis for radiographic Tindings. The Veterinary Journal 196: 64-­‐70.
Parson, D. 2011. Review of Uncertain Path: A Search for the Future of National Parks, by William C. Tweed George Wright Forum 28:17-­‐20.
Peterson, R. O., and R. J. Krumenaker. 1989. Wolves approach extinction on Isle Royale: A biological and policy conundrum. George Wright Forum 6, 10-­‐15.
Peterson, R.O. 1995. The Wolves of Isle Royale – A Broken Balance. Willow Creek Press, Minocqua, Wisconsin.
Peterson, R. O. 1995. The Wolves of Isle Royale, 1994-­‐95 Annual Report. Houghton, MI: Michigan Tech University.
Peterson, R.O., R.E. Page, and K.M. Dodge 1984. Wolves, moose, and the allometry of population cycles. Science 224, 1350-­‐1352.
Peterson, R.O., N. J. Thomas, J. M. Thurber, J.A. Vucetich, and T. A. Waite. 1998. Population limitation and the wolves of Isle Royale. Journal of Mammalogy 79, 828-­‐841.
and C.S. Larsen. 2010. The ecology of arthritis. Ecology Letters 13, 1124–1128.
Post, E., R. O. Peterson, N.C. Stenseth, and B. E. McLaren. 1999. Ecosystem consequences of wolf behavioural response to climate. Nature 401, 905–907.
Potvin, F., P. Beaupré, and G. Laprise. 2003. The eradication of balsam Tir stands by white-­‐tailed deer on Anticosti Island, Québec: a 150 year process. Ecoscience 10, 487–95.
Räikkönen, J., J. A. Vucetich, R. O. Peterson, M. P. Nelson. 2009. Congenital bone deformities and the inbred wolves (Canis lupus) of Isle Royale. Biological Conservation 142, 1027-­‐1033.
Räikkönen J, Vucetich JA, Vucetich LM, Peterson RO, Nelson MP (2013) What the inbred Scandinavian wolf population tells us about the nature of conservation. PLoS ONE 8(6): e67218. doi:10.1371/journal.pone.
0067218
Rapport, D. J., B. L. Lasley, D. E. Rolston, N. Nielsen, C. Qualset, and A. Damania, eds. 2002. Managing for Healthy Ecosystems. Roca Raton, FL: Lewis Publications.
Samuel, W. 2004. White as a Ghost: Winter Ticks and Moose. Edmonton, Canada: Federation of Alberta Naturalists.
Sanders, S. R. 2008. Wilderness as Sabbath for the land. In The Wilderness Debate Rages on: Continuing the Great New Wilderness Debate. M. P. Nelson and J. B. Callicott, eds. Athens, GA: University of Georgia Press, 603-­‐610.
Schlesinger, W., V. Aneja, F. S. Chapin, N. Comerford, J. Gibbs, T. Hrabik, P. Megonigal, M. Turner, J. Whitaker. 2009. Strategic Plan for ScientiTic Research in Isle Royale National Park. Schoener, T.W. 2011. The newest synthesis: understanding the interplay of evolutionary and ecological dynamics. Science 331: 426–429.
Schmitz, O. 2004. Perturbation and abrupt shift in trophic control of biodiversity and productivity. Ecology Letters 7:403–409. Seal, U.S., ed. 1994. A Plan for Genetic Restoration and Management of the Florida Panther (Felis concolor coryi), Report to the US Fish and Wildlife Service, Conservation Breeding Specialist Group.
Peterson, R.O., J.A. Vucetich, G. Fenton, T.D. Drummer, 43
Sinclair, A.R.E. 1998. Natural regulation of ecosystems in protected areas as ecological baselines. Wildlife Society Bulletin 26: 399-­‐409
moose (Alces alces) population of Isle Royale. Proceedings of the Royal Society, London B 271, 183-­‐189.
Steffen, F., Berger, M., Morgan, J.P., 2004. Asymmetrical, transitional, lumbosacral vertebral segments in six dogs: a characteristic spinal syndrome. Journal of the American Animal Hospital Association 40, 338–344.
Vucetich, J.A. and R.O. Peterson. 2004b. The inTluence of prey consumption and demographic stochasticity on population growth rate of Isle Royale wolves (Canis lupus). Oikos 107, 309-­‐320.
St Louis, V.L., J.W. Rudd, C.A. Kelly, R.A. Bodaly, M.J. Paterson, K.G. Beaty, R. H. Hesslein, A. Heyes, and A. R. Majewski. 2004. The rise and fall of mercury methylation in an experimental reservoir. Environ Sci Technol. 38:1348-­‐58.
Vucetich, J.A. and R.O. Peterson. 2007. Ecological Studies of Wolves on Isle Royale. Annual Report 2006–
2007. Michigan Technological University, Houghton, MI. USA.
Taleb, N. 2010. The Black Swan: The Impact of the Highly Improbable. Random House.
Vucetich, J.A. and R.O. Peterson. 2008. The Wolves of Isle Royale, 2007-­‐08 Annual Report. Houghton, MI: Michigan Tech University.
Tallmon, D.A., Luikart G., Waples R. 2004. The alluring simplicity and complex reality of genetic rescue. Trends Ecol. Evol. 19:489–496
Vucetich, JA, MP Nelson, J Räikkönen, RO Peterson. 2009. The logic of persistence. Biological Conservation 143(3): 533-­‐534.
Turner, J.M. 2002. From Woodcraft to ‘Leave No Trace’: Wilderness, Consumerism, and Environmentalism in 20th century America. Environmental History 7, 462-­‐484.
Vucetich, J.A. and R.O. Peterson. 2011. The Wolves of Isle Royale, 2010-­‐1 Annual Report. Houghton, MI: Michigan Tech University.
Turner, M., S. L. Collins, A. L. Lugo, J. J. Magnuson, T. S. Rupp, and F. J. Swanson. 2003. Disturbance Dynamics and Ecological Response: The Contribution of Long-­‐
Term Ecological Research. Bioscience 53, 46-­‐56.
U. S. National Park Service. 1999. Isle Royale: General Management Plan.
U. S. National Park Service. 2006. Management Policies 2006: The guide to managing the National Park Service. (URL: www.nps.gov/policy/mp/policies.html)
Vila, C. et al. 2003. Rescue of a severely bottlenecked wolf (Canis lupus) population by a single immigrant. Proc. R. Soc. Lond. B 270: 91 – 97.
Vucetich, J.A. 2010. Wolves, Ravens, and a new purpose for science. In Moral Ground: Ethical Action for a Planet in Peril. K.D. Moore and M.P. Nelson, eds. San Antonio, TX: Trinity University Press, 337-­‐342.
Vucetich, J.A., M. Hebblewhite, D. W. Smith, and R. O. Peterson. 2011. Predicting Prey population dynamics from kill rate, predation rate and predator-­‐prey ratios in three wolf-­‐ ungulate systems. Journal of Animal Ecology, in press.
Vucetich, J.A. and R.O. Peterson. 2004a. The inTluence of top-­‐down, bottom-­‐up, and abiotic factors on the 44
Vucetich, J.A. and R.O. Peterson. 2012. Ecological Studies of Wolves on Isle Royale. Annual Report 2011–
2012. Michigan Technological University, Houghton, MI. USA. Vucetich, J.A. and R.O. Peterson. 2013. Ecological Studies of Wolves on Isle Royale. Annual Report 2012–
2013. Michigan Technological University, Houghton, MI. USA.
Vucetich, J.A. and M.P. Nelson. 2007. What are 60 warblers worth?: killing in the name of conservation. Oikos 116, 1267-­‐1278.
Vucetich, J.A. and M.P. Nelson. In press. The InTirm Ethical Foundations of Conservation. In Ignoring Nature, M. Bekoff & S Bexell, eds., University of Chicago.
Vucetich, J.A., M.P. Nelson, J. Räikkönen, R.O. Peterson. 2009. The logic of persistence. Biological Conservation 143, 533-­‐534.
Vucetich JA, MP Nelson, RO Peterson. 2012. Managing wolves on Isle Royale, icons of wilderness culture in a changing world. George Wright Forum 29:126-­‐147.
Vucetich, J.A., R. O. Peterson, and T. A. Waite. 1997. Effects of social structure and prey dynamics on extinction risk in gray wolves. Conservation Biology 11, 957-­‐965.
Vucetich, J.A., R.O. Peterson, and T.A. Waite. 2004. Raven scavenging favours group foraging in wolves. Animal Behaviour 67, 1117-­‐1126. Vucetich, J.A., R.O. Peterson, and M.P. Nelson. 2010. Will the future of Isle Royale wolves and moose always differ from our sense of their past? In The World of Wolves, New Perspectives on Ecology, Behaviour and Policy. M. Musiani, L. Boitani, and P. Paquet, eds. Calgary, CA: University of Calgary Press, 123-­‐154.
Vucetich, J. A., and T. A. Waite. 1998. On the interpretation and application of mean extinction times. Biodiversity and Conservation 7:1539-­‐1547.
Wigger, A., Julier-­‐Franz, C., Tellhelm, B. and Kramer, M. 2009. Lumbosakraler Übergangswirbel beim Deutschen Schäferhund: HäuTigkeit, Formen, Genetik und Korrelation zur Hüftgelenksdysplasie. Lumbosacral transitional vertebrae in the German shepherd dog: prevalence, classiTication, genetics, and association with canine hip dysplasia. [In German with English summary] Tierärtzliche Praxis 37: 7-­‐13.
Wilmers, C.C., E.S. Post, R.O. Peterson, and J.A. Vucetich. 2006. Predator disease out-­‐break modulates top-­‐down, bottom-­‐up and climatic effects on herbivore population dynamics. Ecology Letters 9, 383-­‐389.
Wilton, M.L. and D.L. Garner. 1993. Preliminary observations regarding mean April temperature as a possible predictor of tick-­‐induced hair-­‐loss on moose in south-­‐central Ontario, Canada. Alces 29, 197-­‐200.
Woodley, S. 2010. Ecological integrity: a framework for ecosystem-­‐based management. In Beyond Naturalness. D.N. Cole and L. Yung, eds. Island Press, Washington DC, 106-­‐ 124. Wu, J. and O.L. Loucks. 1995. From Balance of Nature to Hierarchical Patch Dynamics: A Paradigm Shift in Ecology. The Quarterly Review of Biology 70, 439-­‐466.
Young, T.P., D. A. Petersen, J. J. Clary. 2005. The ecology of restoration: historical links, emerging issues and unexplored realms. Ecology Letters 8: 662-­‐673.
45
APPENDIX TO CHAPTER 1: Canine Parvovirus
TO BE WRITTEN SOON
46
APPENDIX TO CHAPTER 2
I. Evidence that wolves are an important part of Isle Royale’s wilderness character
The General Management Plan for Isle Royale (GMP) offers important evidence that the N.P.S. has a responsibility to preserve Isle Royale’s wilderness character and ecological integrity, and that wolves are an important element of that wilderness character (U.S. NPS 1999). SpeciTically, one of the park’s Tive Purposes is to “preserve and protect the park’s wilderness character.” Moreover, two of the three Characteristics of Isle Royale that make it signiTicant are (i) the wolves and moose of Isle Royale, and (ii) Isle Royale’s remote biogeography. The third signiTicance item refers to the Tisheries of Isle Royale. The GMP explains how the “Purpose” and “SigniTicance” of the park are derived from the park’s enabling legislation. Moreover, the GMP states that the h i g h e s t p r i o r i t i e s f o r n a t u r a l r e s o u r c e management in Isle Royale include: (i) “primary goal of natural resource management is to preserve the ecological integrity of Isle Royale”, and (ii) “convene a panel of NPS and other subject matter experts to identify and evaluate potential actions for managing the wolf population if viability becomes a concern.”
Other evidence suggesting that wolves are an important component of Isle Royale’s wilderness character include: • Two of the most prominent artistic depictions of Isle Royale depict Isle Royale wolves. SpeciTically, wolves and moose are the central Tigures in Charlie Harper’s depiction of Isle Royale and in the cover image of the free map of Isle Royale made available to every park visitor. • The public’s interest in learning more about the wolves and moose of Isle Royale, which is indicated by (i) the success of the Isle Royale wolf-­‐moose project’s outreach program (see Appendix 2), and (ii) the most prominent displays in the Isle Royale Visitor Center at Windigo feature wolves and moose. • The NPS staff led the organization of a multi-­‐
day event to celebrate the 50th anniversary of the wolf-­‐moose project. The celebration was been repeated at three venues (Duluth, MN; Houghton, MI; Isle Royale National Park). More than 3,000 people were present for some portion of these celebrations, including U.S. Senator Carl Levin’s senior aide, the NPS Associate Director for Science and Natural Resource Management, the Midwest regional director of the NPS, and the Asst. Secretary of the Interior.
II. Summary of outreach activities associated with Isle Royale wolf-­‐moose research
Below is an annotated list of recent outreach activities associated with the Isle Royale wolf-­‐
moose project:
• Film.
¬ Fortunate Wilderness, is a feature-­‐length Tilm by George Desort (www.fortunatewilderness.com) that describes the Isle Royale wolf-­‐moose project. It premiered in July 2008, has been shown at 20 venues throughout the Midwest and Canada (more than 2,500 in attendance) and broadcast on 30 different public TV stations, with an estimated, total audience of 10,000. Fortunate Wilderness was released on DVD in June 2009, and has since sold more than 1,000 copies.
¬ Alces alces: uncut is a short Tilm that was shown at Tilm festivals and art galleries in Houghton (MI), Ann Arbor (MI), and Washburn (WI). Both Tilms feature wolf-­‐moose research.
• Books and other print media for Popular Audiences. 47
¬ The Wolves of Isle Royale, A Broken Balance (Univ. Mich. Press, 2008) by R. Peterson is a popular account of the project’s research Tindings. ¬ A View from the Wolf’s Eye (Isle Royale Nat. Hist. Assoc., 2008) by C. Peterson is a memoir that expresses reverence for Isle Royale and gratitude for opportunities to serve wolf-­‐moose research and Park visitors. ¬ Winter Study (Putnam, 2008) by N. Barr is a Tictionalized, though informative, account of the annual winter study at Isle Royale. In April 2008, Winter Study made the New York Times Best-­‐
Seller list at #10 for hard-­‐cover Tiction. ¬ Notes from the Field, presented in journal format, details the work and observations of each annual winter Tield season. Notes from the Field shares with the general public how observations are transformed into discoveries, and describes how at least one scientist relates research on nature with a broader relationship to nature. The Notes from the Field are Tirst presented as a daily blog (www.isleroyalewolf.org) and later in the year in hardcopy.
¬ The Wolves of Isle Royale, Annual Report. The annual reports, produced by J. Vucetich and R. Peterson, present each year’s scientiTic Tindings for a general audience. • Web-­‐based Outreach. The Wolves and Moose of Isle Royale website (www.isleroyalewolf.org) is aimed at a general audience and continues to be visited by >10k people annually. More than 1,100 people have signed-­‐up to receive occasional research updates via email. • Public involvement in research. ¬ Members of the public have an opportunity each year work with the Isle Royale wolf-­‐moose project during week-­‐long research expeditions. Participants learn about the project and help us collect vital data. In the past Tive years, 170 people (many of them teachers) have participated in the expeditions.
¬ For more than three decades, two to four undergraduate students are selected as interns or Tield assistants from among dozens that apply 48
from three continents. These undergraduates live in the Tield for one to three months with project leaders. Former assistants include Douglas Smith (director of Yellowstone wolf research) and Michael Phillips (director of Turner Endangered Species Fund). • Science Museum Exhibits. ¬ Since 2007, a 1,000 ft2 exhibit featuring the project’s scientiTic discoveries has been viewed by >5,000 people during 12 months of display at three different venues (Carnegie Museum, Houghton, MI; Library of Univ. Minn.–Duluth; Hartley Nature Center, Duluth, MN). ¬ Increasingly, since 2000, the summer Tield station at the historic Bangsund cabin has served as a Tield museum featuring the world’s largest collection of antlered skulls of bull moose, other displays, and informal presentations by the PIs. During 2009-­‐2011, this Tield site was visited by more than 3,200 visitors.
• The Arts. – The wolf-­‐moose study has been a means to connect the arts and sciences. ¬ In Oct/Nov 2008, the Omphale Gallery (Calumet, MI) featured Thinking Like an Island, a collection of 38 still images depicting wolf-­‐moose research from an artistic perspective. A portion of this exhibit was also shown at The Gallery Project (Ann Arbor, MI, Oct 2008) for an exhibit designed to connect science and art. More than 2,000 people visited one of these venues. The exhibit was viewed by >30,000 visitors to the International Wolf Center (Ely, MN) during 2010-­‐2011. ¬ The moose bones collected during wolf-­‐moose research have been featured in work by at least 4 professional artists and a major art exhibition in Minneapolis, MN. Internationally-­‐recognized artists, R. Bateman and Gendron Jensen, each associated one of their pieces with the wolf-­‐
moose research at Isle Royale.
¬ In fall 2007, there was a nation-­‐wide art contest for high school students. The contest theme was to depict, in art, some scientiTic lesson from wolf-­‐
moose research. • Public presentations. In the past Tive years (2007-­‐2011), associates of the wolf-­‐moose project have delivered more than 200 talks to more than 7,500 members of the general public, mostly National Park visitors and K-­‐12 students.
• Journalism. In the past 5 years, wolf-­‐moose research on Isle Royale was featured by national media on >75 occasions (e.g., Wash Post, Assoc Press, Audubon), and by local or regional media on >25 occasions. • Conservation and Management. ¬ To promote wolf conservation, the Isle Royale project was featured on the 2008 Wolf Awareness Poster, of which 35,000 copies were distributed nationally.
• U.S. Congressional Record. – On 21 July 2008, S e n a t o r C a r l L e v i n e n t e r e d , i n t o t h e congressional record, a statement of gratitude for the Isle Royale wolf-­‐moose project.
• Other educational venues. – Wolf-­‐moose research Tindings are also featured in: i) at least 12 books used as texts for university courses, ii) lecture material for graduate and undergraduate courses taught in at least 20 universities, iii) popular education software such as Ecobeaker (Simbiotic Software, Ithaca, NY) and Wolf Adventures (Bowling Green State Univ.), and iv) more than 12 books or book chapters published by scientiTic presses (e.g., Chicago, Princeton, Blackwell, Sinauer, etc.).
49