Adam Pace
Dr. Combs
English 2010
November 4th, 2015
Article reviews/annotated bibliography
Cook, R. C., Murray, D. L., Cook, J. G., Zager, P., Monfort, S. L., (2001) Nutritional influences
on breeding dynamics in elk. Canadian Journal of Zoology, 79, 845-853
In the article “Nutritional influences on breeding dynamics in elk.” Cook and Murray are
curious to discover more about the timing of and what affects reproduction among elk. Elk
populations are declining across the northwestern of the United States. According to Cook and
Murray they hypothesize the decline may be attributable to depressed pregnancy rates in adult
females and That early pregnancy rates are closely linked to nutrition in the summer and early
autumn. 60%-70% of the females in some Idaho elk herds are involved in depressed late-winter
pregnancy and this is not healthy for an infant. Also depressed late wintery pregnancy rates relate
to poor winter-forage in some conditions. They state that if an elk does not eat enough during
summer and autumn the elk will not lactate and the infant will die. They suspect the number of
elk is dwindling due to the lack of food. Poor nutrition can have a direct and adverse effect on
hypothalamic–pituitary function. Cook and Murray used thirty-three captive female elk to test
how much nutrition really affected reproduction. The elk were housed in six one half acre pens
near Kamela Oregon. These elk were captured as calves from a wild herd at the Starkey
experimental Forest and Range near La Grande, Oregon in 1991 and 1993 and subsequently
bottle-raised. Each pen was devoid of vegetation and contained a barn wit 9-12 stalls designed
for individual feeding and collection of physiological samples (blood, urine, and feces). The
Facility in which all this took place permitted researchers o track reproductive activity, evaluate
body conditions, and manipulate food rations. They then manipulated what the 33 female elk ate
lasting from June 21st 1997 through November 4 1997. They split the elk into 3 different feeding
groups. (Low, medium, and high) Low nutrition diet was designed to mimic DE levels that
commonly occur in low-elevation xeric forests in the Blue Mountains in northeastern Oregon.
They assumed the low diet represented the poorest quality forage encountered by a wild elk in
this region during summer and autumn. The Medium nutrition diet was between the high and low
nutrition treatments. Before the experiment started all elk were fed the same quality of hay that
lead to the same overall DE content. 12.35 kj/g. These Elk were fed accordingly from JuneNovember. As it got closer to November the food they were given slowly was less. This was
supposed to mimic what actually happens in the wild as winter rolls in and food becomes scarce.
One adult wild bull was placed in each pen from September 5th- November 4th and the females
were observed daily from dawn until dusk. No female displayed more than one period of estrus.
The results they received from there test were that elk high- and medium-nutrition
treatments bred more than the females found in the low nutrition treatment. Only 1 of 10 females
fed a low energy content diet bread compared with 9 of the 10 females subject to each of the
other higher energy diets. The females in the low energy diet apparently failed to enter a
reproductive cycle and thus did not ovulate. They found in their results that the elk that were fed
a higher energy diet had an earlier date of breading. High energy diet September 29h, Medium
energy diet October 7 and the one female that bread in the low category bred on October 27th.
They concluded that there results supported there hypothesis and that nutritional plane impacted
reproductive function in adult female elk.
This source is important to me because I want to know why elk and deer bread at different times.
This article can help me clearly state why elk breed when they do and why they do. I can take
what I leaned in this article and apply it to my research project. I plan to use many part of it
especially how nutrition affects when an elk breeds. In the 3rd paragraph of the results section I
plan to use to use the results they found about how nutrition affects when and if an elk will
breed. I also plan to use the piece in the second paragraph of the methods when nutritional facts
of the Oregon forests are brought up. For the most part I don’t want to quote this article directly
but I want to use what I’ve learned. Write it in my own words and provide a source where and
when I need them. For example I know I will use the 2 sources I talked about earlier in this
paragraph.
Gill, B., Ellenberger J. H., (2001) Effect of adult sex ratio on mule deer and elk productivity in
Colorado. Journal of Wildlife Management, 65, 543-551
In the article “Effect of Adult Sex Ratio on Mule Deer and Elk Productivity in Colorado” Gill
and Ellenberger show a curiosity in post-harvest: female ratios during the breeding period. They
hypothesized the cause of this decline as the male: female ratio during breeding period. They
examined Colorado division of Wildlife deer and elk population composition data obtained from
a helicopter surveys to see whether sex ratios explained variation in the young: female ratios.
Data or both deer and elk supported a response of young: 100 female ratios to the male; 100
female ratios during the previous year. The observed ratios were about 0.25 fawns: 100 Does per
1 buck: 100 does for deer. Or in other words the buck to doe ratio sucked and so did the fawn to
doe ratio in deer. In elk it wasn’t very different. 0.28 calves: 100 cows per 1 bull: 100 cows. In
other words the ratio found in elk were almost exactly the same. They observed these ratios
during 1975-1995. They hypothesized the low ratio of fawn:doe and calve:cow was due to the
low ratio of buck:doe and bull:cow. They suspected the numbers of fawn directly correlated with
the number bull/buck there when compare in a buck:doe ratio and bull:cow ratio. The number of
deer and elk was dwindling quickly and Gill and Elllenburger knew something need to be done
in order to help the existence of mule deer and elk.
They assumed that there are 3 conceivable effects resulting from low male:female ratios
and or low mature male:female ratios. (1) late breeding by some females resulting in later
parturition and lower survival of offspring; (2) lack o synchrony in parturition resulting in
increased mortality of offspring from predation; and (3) failure for some females to breed.
(Introduction 1st paragraph) They then go on to explain to how in other studies including one in
mule deer the buck:doe ratio has only shown a statistical significant relationship between
fawn;doe ratios in 2 of 34 mule deer units in the Arizona. They also go on to quote another study
that was done regarding yearly males and reproduction and say that after breeding from yearling
male no evidence was found that a yearling male cannot reproduce. A male is a male in the
animal world and ae doesn’t matter is what they are saying. They also quote another article that
states that a ratio of six males;100 females is sufficient for high pregnancy rates and early and
synchronous breeding. They also say they observed early, synchronous breeding and hig
pregnancy rates with 18 3-year old bulls per 100 cows in a northern Utah region. The elk found
in this region are hunted intensely and the pressure from hunting did not negatively affect
productivity of the young bulls. (Introduction 2nd paragraph) a few other sources are then used
that state that yearly bulls are just as capable as mature bulls when it came to breeding. One
article cited stated that when the buck:doe or bull:cow ratio drops below 10:100 then the
infant:mother ratio is directly affected. To find out for themselves Gill and Ellenburger dived
Colorado into 53 analysis units for mule deer and 49 units for elk. Every year after hunting
season. During December and January for deer and January and February for elk. They would fly
above these units in a helicopter to survey the age and sex ratios between the animals that were
let after hunting prior to antler drop. They attempted to fly the same routes or non-random routes
in areas they knew were inhabited by deer or elk classifying as many deer and elk as they could
(Methods first paragraph). Deer and elk were classified into groups. Young of the year, females
or antlerless, and males or antlered. Deer and elk males were classified as yearling or older males
based on antler size and number of points. They used data from 462 mule deer and 465 elk. The
results they found from there study supported there hypothesis. Male:female ratio does effect
young:female ratio. The more males you have the more young there will be.
This source it talks about how the reproduction of elk and deer are changed. I plan on
using several paragraphs from this article. All of which I have talked about in the paragraphs
leading up to this one. I plan to use this source to show a few examples of how the breeding
season of deer and elk are effected. It also had a few other sources that caught my attention that I
might go back and check out. I also plan on using what was said in the introduction second
paragraph about how elk that are hunted intensely still are able to reprove many numbers if there
are more than 10 bulls to every 100.
Wolff, J. O., Horn, T. V. (2003). Vigilance and foraging patterns of the American elk during rut
habitats with and without predators. Canadian Journal of Zoology, 81(2), 266-271.
Reproduction among Elk and Mule deer correlates directly with predation. The more time
a Mule Deer or Elk spend running and evading predators the less time the animal will have to
reproduce. This article suggest that the Deer or Elk rutting depends on how many predators the
animals have to be aware off. The less predators there are in the area the more the animal can
focus reproducing. Elk are two sometimes three times the size of mule. The predators that they
face are not the same predators Deer face. This article suggest that the size of the elk make help
them to feel safe and comfortable in their environment. Knowing there are not many predators
around which make it easier for them to enter into the rut. And which usually causes them to
enter into the rut before deer do. Deer on the other hand have many predators compared to an
Elk. This affects the deer and the time of season the deer choose to mate during. Deer rut in
November, They group up for the winter and stay in herds. They do this to beat the cold and to
be in a safer environment. 2 eyes are always better than one.
The motivation behind this study was that Elk found in yellow stones national park would spend
more time running from predators then elk found in Rocky mountain national park. They are
motivated to improve the number of Deer and Elk in the Yellowstone area. They hypothesized
that the number of predators an Elk has affects reproduction thus reducing the number of Elk in
that curtain area. This source is important to me because I am studying why Deer rut later in the
year compared to Elk. This article has some specific evidence to why Elk and Deer rut when they
do. I can use this source to provide evidence and to prove why Deer and Elk rut when they do.
Robinette, W. L., Gashwiler, J. S., (1950) Breeding season, productivity, and fawning period of
the mule deer in Utah. The Journal of Wildlife management 14(4), 457-469
In the article “breeding season, productivity and fawning period of mule deer in Utah”
Robinette and Gashwiler studied when a mule deer enters and ends breeding season. And
roughly how many embryos one doe can have. This information is important in order to establish
hunting seasons. They state that for a number of years pregnancy records have been secures for
from mule deer found dead in Utah. Many of the deer that died were victims of automobiles or
railroad accidents, others the result of control measures. Which means that they were hunted and
killed. A few were collected for scientific purposes and still others died of mal nutrition and
other natural causes. Harsh winters and winter ranges with minimal food make collecting lots of
specimens possible.
The breeding season of mule deer in Utah is generally considered to include the month of
November and the first half of December. Bucks killed in the last half of hunting season (end of
October) generally have swollen necks which indicates they are approaching the breeding
season. (Breeding 2nd paragraph pg457). This was discovered by two methods. (1) Aging
embryos from does whose date of death was known and calculating back to the date of
conception; And (2) using the estimated ages of tagged fawns to determine the birth dates of
conception. A total of 43 pregnant does with embryos large enough to measure, and the whitetail growth curve would age mule deer embryos. They also cover when a fawn is born and what
are the chances of it being born on a later or earlier date. They concluded that deer breed in
November and early December. And the fawns are born from June 3rd to august 19th.
I plan to use this article provide a specific date of the breeding season of mule deer
(PG457 breeding 1st paragraph.) and to provide dates of when fawns are born.(458 Breeding last
paragraph)
Kucera, T. E., (1978) Social Behavior and breeding system of the desert mule deer. Journal of
Mammalogy, 59(3), 463-476
In the article “social behavior and breeding system of the desert mule deer”. Kucera
Observed mule deer in Big Sky Bend National Park, Texas, during the rut to determine and to
described and quantify social behavior. The deer were in groups that sized from one to 24 with a
mean of 5.2. Male-male acts such as head-toss, rub –urination, antler thrash-forehead rub., and
chase were performed in dominance and agonistic interactions most frequently by the larger
antler classes , and were inversely associated with rut. Sparring was inversely associated with the
rut and was most frequently in the smaller antler classes. Among female-female acts, the strike
and flail were inversely associated with the rut. They say that tending bonds were formed
between individual bucks and estrous does. In the past lots of research has been contradicting to
someone else’s research that was done. Some scientist would state the mule deer buck herd there
does during breeding and another would state that the buck chooses one doe in specifically and
mates with her and then goes and finds another doe. Both of these statements contradict the
other. And Kucera wanted to prove to everyone the real nature of mule deer during breeding
system and how they act and how a dominant male is found or chosen. In the last paragraph of
the introduction the purpose is actually stated. “The purpose of this study was to describe and
quantify behavior during rut and to determine the breeding system of the desert mule deer”.
More than 400 hours of direct observation of deer were made from distances of 5 meters
to 1 kilometer. The mule deer were observed through binoculars and spotting scopes. Also a
photographic record was taken using a camera. About half of the observations made were made
from some type of automobile. The rest while stalking the animals on foot. The automobile was
preferred because, serving as a blind, It disturbed the deer much less then than a person on foot.
Night observations by spotlight were attempted but the terrain and vegetation mad these
observations almost impossible. Buck were recognized as individuals by antler size and
configuration, and by distinctive markings such as scars and ear abnormalities. Photos were
taken of more than 70 bucks to aid in field identification. Some of these bucks were viewed as
many times as 14 times. Bucks were classified as yearling, 3-4 point, 5-6 point, 9-10 point, and
greater than 10 point. The older a mule deer buck is the greater number of points it will have.
The does on the other hand were very hard to distinguish as an individual. Only a select few with
distinctive markings or abnormalities were viewed as individuals. The behavioral acts and social
interactions were recorded on a minute-by-minute basis, noting sex, age, antler class, and when
possible, known individuals. This data was numbered and analyzed in terms of the number of
acts per active hour. Time spent bedded was not included into the frequency calculations, as little
behavior occurred when deer were bedded. A total of 399 sightings of deer were recorded. And
1,340 hours of active deer were recorded. Social interactions also were analyzed by sex and size
of class matrices. Prior to the rut, most bucks were in bucks-only groups but during the most
intense rutting period 90% of bucks
I plan to use this source in describing what deer do or what their breeding system is.
(Discussion Pg472-475)