DRAFT
March 2012
PLANTS
Kelso Creek Monkeyflower (Mimulus shevockii)
Kelso Creek Monkeyflower
(Mimulus shevockii)
Legal Status
State: S21
California
Rare
Plant
2
Rank: 1B.2
Federal: Bureau of Land
Management Sensitive
Critical Habitat: N/A
Recovery Planning: N/A
Photo courtesy of Steve Schoenig.
Notes: Kelso Creek monkeyflower was proposed for federal listing in
1994 (59 FR 50540–50550). The proposal was withdrawn in 1998
when it was determined that Kelso Creek monkeyflower was not
threatened with extinction and therefore did not meet the definition
of a threatened or endangered species (63 FR 49065–49075).
Taxonomy
Kelso Creek monkeyflower (Mimulus shevockii) is an annual herb now
placed in the lopseed family (Phrymaceae), which was recently
segregated from the figwort family (Scrophulariaceae) (Jepson Flora
Project 2011; Beardsley and Olmstead 2002). The species was
originally described by L.R. Heckard and R.C.F. Bacigalupi in 1986
(Heckard and Bacigalupi 1986) and named to honor its discoverer,
James Shevock. A search of older collections revealed several
unidentified or misidentified specimens that belong in M. shevockii.
Kelso Creek monkeyflower stands approximately 2 to 12 centimeters
(0.8 to 4.7 inches) in height. A full physical description of the species
can be found in the original description (Heckard and Bacigalupi 1986),
in the Jepson eFlora (Jepson Flora Project 2011) and Elvin (2006).
1
2
S1: Imperiled; X.2: Threatened.
1B: Rare, threatened, or endangered in California and elsewhere. X.2: Fairly endangered in California.
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Species Accounts
March 2012
DRAFT
March 2012
PLANTS
Kelso Creek Monkeyflower (Mimulus shevockii)
Distribution
General
The Kelso Creek monkeyflower is restricted to a very small range,
approximately 20 square miles, in the southern Sierra Nevada Foothills
and western edge of the Mojave Desert within the Kern River drainage
(Figure SP-P13; Jepson Flora Project 2011; Fraga 2007). All 11 known
occurrences are in Kern County, the majority southwest of Lake
Isabella in the Kelso Creek and Cortez Canyon area, all within an area 5
miles in diameter (CDFG 2012a). Two disjunct occurrences are located
in the Cyrus Canyon and Cyrus Flat area northeast of Lake Isabella, over
12 miles northwest of the other populations (CDFG 2012a).
Distribution and Occurrences within the Plan Area
Historical
There are no historical records for this species within the Plan Area.
All occurrences have been seen since 2008 and are presumed extant
(CDFG 2012a).
Recent
Of the eleven total occurrences of Kelso Creek monkeyflower, seven are
in the Plan Area (Figure SP-P13). Five of these are in the Ridgecrest
Recreation Area (RA) on lands managed by the Bureau of Land
Management (BLM) (CDFG 2012a). Two are further south on the west
and east sides of Kelso Valley and are located partially on BLM lands
and partially on private land (CDFG 2012a; 59 FR 50540–50550).
Natural History
Habitat Requirements
Kelso Creek monkeyflower occurs predominately in loamy, coarse
sands on alluvial fans, dry streamlets, or washes and granitic deposits
within Joshua tree or California juniper xeric woodlands (59 FR
50540–50550; Heckard and Bacigalupi 1986). Substrates where Kelso
Creek monkeyflower are found are generally granitic or metamorphic,
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Species Accounts
March 2012
DRAFT
March 2012
PLANTS
Kelso Creek Monkeyflower (Mimulus shevockii)
and sandy or gravelly (CNPS 2011). However, the population near
Cyrus Flat grows on finer soils developed from metasedimentary
rocks (CDFG 2012a; Heckard and Bacigalupi 1986). The California
Native Plant Society (CNPS) (2011) reports an elevation range for this
species from 800 to 1,340 meters (2,625 to 4,396 feet). However, the
CNDDB (CDFG 2012a) includes one occurrence at 4,500 feet. Species
strongly associated with Kelso Creek monkeyflower include pygmy
poppy (Canbya candida), silver cholla (Cylindropuntia echinocarpa),
purple sage (Salvia dorrii), golden gilia (Leptosiphon aureus),
Tehachapi monkeyflower (Mimulus androsaceus), Fremont’s
monkeyflower (M. fremontii), and cheesebush or burrobrush
(Ambrosia salsola) (Heckard and Bacigalupi 1986). Table 1 lists
primary habitat associations and parameters for Kelso Creek
monkeyflower.
Table 1. Habitat Associations for Kelso Creek Monkeyflower
Land Cover Type
Joshua tree
woodland, pinyon
and juniper
woodland, alluvial
fans/dry streamlets/
desert washes
Habitat
Designation
Habitat
Parameters
Supporting
Information
Primary
Granitic or
metamorphic,
sandy or
gravelly
substrates;
2,625 to 4,500
feet
Heckard and
Bacigalupi
1986; CNPS
2011; CDFG
2012a; Elvin
2006;
Audubon
2011
Reproduction
Kelso Creek monkeyflower is a tiny ephemeral winter annual that
blooms from March to May (CNPS 2011). It is unknown whether
Kelso Creek monkeyflower is self-sterile or self-fertile (Elvin 2006).
Given the relative size of its corolla, the nectar guide patterning, and
corolla colors, Kelso Creek monkeyflower is probably outcrossing,
and is probably pollinated by small solitary native bees; soft-wing
flower beetles (Trichochrous sp.) have been observed visiting
flowers (Fraga 2007).
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Species Accounts
March 2012
DRAFT
March 2012
PLANTS
Kelso Creek Monkeyflower (Mimulus shevockii)
It fruits from April to June (Fraga 2007). The fruit is a 0.25-inch
capsule that contains more than 100 seeds and is dehiscent at the end
and along both sutures (Heckard and Bacigalupi 1986). Although not
directly observed, water is a likely seed dispersal mechanism since
Kelso Creek monkeyflower occurs in washes (Elvin 2006).
The role of the seedbank is probably very important for the long-term
survival of populations. It is known from similar annual Mimulus
species that even in high rainfall years, some fraction of seed stays
dormant and remains in the seed bank (Fraga 2007). Kelso Creek
monkeyflower does not germinate at all in drought years. The amount
and timing of rainfall affect the number of seeds that germinate, the
timing of germination, and the size and longevity of desert annuals
(Fraga 2007).
Ecological Relationships
Although Kelso Creek monkeyflower is highly restricted in
distribution, it appears to be common where it occurs in years of
ample rain (Fraga 2007). It does not appear to have very exacting
habitat requirements (Fraga 2007), although there appears to be
hundreds of acres of apparently suitable habitat that are unoccupied
(Heckard and Bacigalupi 1986). In wet years, Kelso Creek
monkeyflower can form carpets on the desert floor, but can be
difficult to locate in drier years (CPC 2011).
Kelso Creek monkeyflower hybridizes with its closest relative
Tehachapi monkeyflower (Mimulus androsaceus) (Audubon 2011;
CDFG 2012a). This suggests that the Kelso Creek monkeyflower may
have evolved from Cyrus Canyon and spread southward to other
locations in the Kern and Kelso Valleys (Audubon 2011).
Little additional information is known of its life history and ecological
relationships.
4
Species Accounts
March 2012
DRAFT
March 2012
PLANTS
Kelso Creek Monkeyflower (Mimulus shevockii)
Population Status and Trends
Global: G2, Imperiled (NatureServe 2011, conservation status last
updated in 2009)
State: S2, Imperiled (CDFG 2012b)
Kelso Creek monkeyflower has probably always been a rare species
with a very narrow distribution (Elvin 2006). All known occurrences
of Kelso Creek monkeyflower, except one whose exact location is
unknown, were last surveyed systematically in 2008 (CPC 2011; CDFG
2012a). In some cases, timing was not optimal for detection of the
species. Based on the population estimates made in 2008 and earlier
estimates for those that were not visible in 2008, there were at least
an estimated 53,400 Kelso Creek monkeyflower individuals
throughout its range (CDFG 2012a). However, the population trend is
unknown and because this plant is an annual, population sizes may
vary greatly from year to year (CDFG 2012a; Fraga 2007). In addition,
long-term trends are difficult to assess since the species was not
described until 1986. Plants were extirpated when Lake Isabella was
created (CDFG 2012a).
Threats and Environmental Stressors
Kelso Creek monkeyflower is threatened by urbanization, off-highway
vehicle use, agricultural land conversion, road maintenance, cattle
grazing, habitat loss from water inundation, fire suppression
activities, and competition from non-native species (59 FR 50540–
50550; CNPS 2011; NatureServe 2011). The extremely limited
distribution of this plant puts it at risk of stochastic extinction events
(Elvin 2006).
This species is primarily threatened by the current or potential
destruction, modification, or curtailment of its habitat or range.
Mobile home and subdivision development and associated grading
threaten or have impacted six of the eleven occurrences (CDFG
2012a). Cattle grazing, introduction of non-native plant species, and
conversion of habitat to orchards have begun to modify the landscape
and threaten Kelso Creek monkeyflower occurrences and limited
natural habitat (Elvin 2006; CDFG 2012a).
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Species Accounts
March 2012
DRAFT
March 2012
PLANTS
Kelso Creek Monkeyflower (Mimulus shevockii)
Of the seven occurrences within the Plan Area, three are entirely on
BLM Ridgecrest RA lands, two are partially on BLM Ridgecrest RA
lands and partially on private lands, and two are partially on BLM land
outside of Ridgecrest RA and partially on private lands (CDFG 2012a).
Although occurrences on BLM lands are provided some protection,
there are still documented threats to these populations (Elvin 2006).
All of the populations on private land are at risk of mobile home or
subdivision development. Populations located on BLM lands adjacent
to private property are also affected by this threat (Elvin 2006).
The effect that highway and road maintenance has on populations on
or adjacent to private property is twofold: improved access has
increased development and the additional traffic has created pressure
to add or widen roads. At least one population has been bisected by
road development. Off-highway vehicle use directly impacts or
threatens approximately half of the known occurrences throughout its
range (Elvin 2006). At least one population site has been highly
disturbed, probably from uncontrolled overgrazing during drought
(CDFG 2012a). Water developments and impoundments also
potentially threaten this species (Elvin 2006).
Conservation and Management Activities
The West Mojave Plan includes monitoring and adaptive management
prescriptions for the Kelso Creek monkeyflower (BLM 2005). Surveys
will be continued on suitable habitat on public land. Spillover impacts
on public lands from adjacent private land will be documented. The
BLM will make a determination of regional rangeland health
standards in the Rudnick Common Allotment within 5 years of Plan
approval. Adaptive management activities for the species are:
conservation area boundary adjustment based on survey results,
route changes to avoid occupied habitat, potential adjustments in
grazing practices and Allotment Management Plans in Kelso Valley
based on results of the rangeland health determinations, pursuit of
land purchase or exchange, and fencing of BLM/private property
boundaries if spillover impacts are evident (BLM 2005).
Lands trusts, such as the Kern River Preserve, Kern Valley Heritage
Foundation, or the Mojave Desert Land Trust, may acquire land that is
currently zoned for development on which Kelso Creek monkeyflower
6
Species Accounts
March 2012
DRAFT
March 2012
PLANTS
Kelso Creek Monkeyflower (Mimulus shevockii)
occurs (CPC 2010). In 2006, Audubon purchased a 1,660-acre parcel in
Cyrus Canyon, which was then transferred to the BLM to be conserved
in perpetuity (Audubon 2011). The land is located northwest of the
Kern River Preserve in juniper woodland and upper Sonoran grassland.
BLM botanical surveys found thousands of individuals of Kelso Creek
monkeyflower and the hybrid between this species and Tehachapi
monkeyflower in this area (Audubon 2006, 2011).
A Conservation Plan has been developed for this species that
recommends a monitoring program with standardized protocols,
surveying potential habitat for additional occurrences, and
maintaining an ex-situ conservation seed collection (Fraga 2007).
Conservation objectives include maintaining all existing occurrences,
preserving existing habitat, limiting impacts from disturbances,
establishing an ex-situ maternal line seed collection, assessing the
genetic diversity of the species to identify meta-population dynamics,
and identifying site-specific research needs (Fraga 2007). The
Conservation Plan also prescribes general conservation actions as
well as site-specific actions, and provides an implementation strategy,
to conserve the species (Fraga 2007).
Data Characterization
In 1998, there were approximately 1,600 acres of potential habitat on
BLM land that had not been surveyed (63 FR 49065–49075).
However, surveys of potential habitat were conducted from 2005 to
2007. Although no new occurrences were found as of the spring of
2007 (Fraga 2007), all known occurrences were last surveyed
systematically in 2008, and two new occurrences were recorded in
2008 (CPC 2010; CDFG 2012a).
Little is known of the species’ life history in regard to breeding
systems, pollinators, and germination requirements. The genetic
structure of the species also remains unknown (Fraga 2007).
Management and Monitoring Considerations
Management of this species is dependent upon protecting the known
population sites from development and surface disturbance (Elvin
2006; NatureServe 2011). As much of the surrounding land as
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Species Accounts
March 2012
DRAFT
March 2012
PLANTS
Kelso Creek Monkeyflower (Mimulus shevockii)
possible should also be protected to minimize indirect impacts from
nearby development (NatureServe 2011). As described previously,
other suitable habitat should be surveyed for additional populations,
especially considering there is a substantial amount of development
occurring within the species’ restricted range. Furthermore, all of the
populations could be impacted by fragmentation of the habitat as a
result of development. This highlights the need to conserve and
protect a large, contiguous area of undisturbed land (Elvin 2006).
In addition to additional surveys in suitable habitat, research needs
include a life history assessment to study the breeding systems,
pollinators, and germination requirements by conducting germination
trials. In addition, the genetic structure of the species should be
investigated (Fraga 2007). Though seeds have been collected from the
Cyrus Canyon population for long-term conservation, seeds from the
southern populations near Kelso Creek and Kelso Valley should be
collected (Fraga 2007; CPC 2010).
As a desert annual, fluctuations in population size from year-to-year
in response to rainfall are an important monitoring consideration.
Fraga (2007) suggests annual monitoring for Kelso Creek
monkeyflower following a standardized method so that comparisons
can be made from year to year.
Predicted Species Distribution in Plan Area
There are 144,127 acres of modeled suitable habitat for Kelso Creek
monkeyflower in the Plan Area. Modeled suitable habitat occurs in the
northwestern portion of the Plan Area from 2,600 to 4,500 feet in
elevation. Modeled suitable habitat includes shrub, grassland,
woodland, and riparian vegetation communities with granitic,
metamorphic, or sedimentary substrates. Appendix C includes
specific model parameters and a figure showing the modeled
suitable habitat in the Plan Area.
Literature Cited
59 FR 50540–50550 Proposed Rule: “Endangered and Threatened
Wildlife and Plants; Proposed Endangered or Threatened
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Species Accounts
March 2012
DRAFT
March 2012
PLANTS
Kelso Creek Monkeyflower (Mimulus shevockii)
Status for 10 Plants from the Foothills of the Sierra Nevada
Mountains in California.” October 4, 1994.
63 FR 49065–49075 Proposed Rule; withdrawal: “Endangered and
Threatened Wildlife and Plants; Withdrawal of Proposed
Listing of Two Plants as Endangered, and Four Plants as
Threatened From the Foothills of the Sierra Nevada Mountains
in California.” September 14, 1998.
Audubon. 2006. “Audubon and Partners protect 1,666 acre Cyrus
Canyon.” Audubon California Kern River Preserve. September 5,
2006. Accessed November 22, 2011. http://kern.audubon.org/
2006-Cyrus_Canyon_purchase.htm.
Audubon. 2011. “Kelso Creek Monkeyflower, Mimulus shevockii,
Audubon protects critical habitat up Cyrus Canyon.” Audubon
California Kern River Preserve. Accessed November 22, 2011.
http://kern.audubon.org/MIMSHE.htm.
Beardsley, P.M. and R.G. Olmstead. 2002. “Redefining Phrymaceae:
The Placement of Mimulus, Tribe Mimulaeae, and Phryma.”
American Journal of Botany 89(7): 1093–1102.
BLM (Bureau of Land Management). 2005. Final Environmental
Impact Report and Statement for the West Mojave Plan. A
Habitat Conservation Plan and California Desert Conservation
Area Plan Amendment. January 2005.
CDFG (California Department of Fish and Game). 2012a. “Mimulus
shevockii.” Element Occurrence Query. California Natural
Diversity Database (CNDDB). RareFind, Version 4.0
(Commercial Subscription). Sacramento, California: CDFG,
Biogeographic Data Branch. Accessed November 24, 2011.
http://www.dfg.ca.gov/biogeodata/cnddb/mapsanddata.asp.
CDFG. 2012b. Special Vascular Plants, Bryophytes, and Lichens List.
CNDDB. January 2012. Accessed February 2012.
http://www.dfg.ca.gov/biogeodata/cnddb/
plants_and_animals.asp.
9
Species Accounts
March 2012
DRAFT
March 2012
PLANTS
Kelso Creek Monkeyflower (Mimulus shevockii)
CNPS (California Native Plant Society). 2011. “Mimulus shevockii.”
Inventory of Rare and Endangered Plants. Online ed. Version 801a. Sacramento, California: CNPS. Accessed November 2011.
http://www.cnps.org/inventory.
CPC (Center for Plant Conservation). 2011. “Mimulus shevockii.” CPC
National Collection Plant Profile. Last revised May 25, 2011.
Accessed November 22, 2011.
http://www.centerforplantconservation.org/collection/CPC_V
iewProfile.asp?CPCNum=7634.
Elvin, M. 2006. “Kelso Creek Monkeyflower (Mimulus shevockii).” West
Mojave Plan Species Accounts. U.S. Department of the Interior,
Bureau of Land Management. January 2006. Accessed
November 21, 2011. http://www.dmg.gov/documents/
WMP_Species_Accounts/Species%20Accounts-Plants.pdf.
Fraga, N.S. 2007. “A Conservation Plan for Mimulus shevockii
(Phrymaceae).” Rancho Santa Ana Botanic Garden Occasional
Publications 7. Claremont, California: Rancho Santa Ana
Botanic Garden.
Heckard, L. and R. Bacigalupi. 1986. “Mimulus shevockii
(Scrophulariaceae), a new species from desert habitats in the
Southern Sierra Nevada of California.” Madroño 33:271–277.
Jepson Flora Project. 2011. “Mimulus shevockii.” D.M. Thompson, ed.
Jepson eFlora [v. 1.0]. Berkeley, California: University of
California. Accessed December 5, 2011.
http://ucjeps.berkeley.edu/IJM.html.
NatureServe. 2011. “Mimulus shevockii.” NatureServe Explorer: An
Online Encyclopedia of Life. Version 7.1. Arlington, Virginia:
NatureServe. Last updated July 2011. Accessed November
2011. http://www.natureserve.org/explorer.
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March 2012