Effects of Cougar Predation and Nutrition on Mule Deer Population Declines in the IM Province of the Columbia Basin PDF Download

Author: Robert B. Wielgus
Publisher:
ISBN:
Category : Animal radio tracking
Languages : en
Pages : 52

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Author:
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ISBN:
Category :
Languages : en
Pages : 54

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Book Description
Construction of the Grand Coulee and Chief Joseph dams has resulted in inundation and loss of 29,125 total habitat units for mule deer and irrigation agriculture in many parts the Intermountain Province (IM) of the Columbia Basin. Mule deer in the Shrub-Steppe are ranked high priority target species for mitigation and management and are declining in most portions of the subbasins of the IM. Reasons for the decline are unknown but believed to be related to habitat changes resulting from dams and irrigation agriculture. White-tailed deer are not ranked as target species and are believed to be increasing throughout the basin because of habitat changes brought about by the dams and irrigation agriculture. Recent research (1997-2000) in the NE IM and adjacent Canadian portions of the Columbia Basin (conducted by this author and funded by the Columbia Basin Fish & Wildlife Compensation Program B.C.), suggest that the increasing white-tailed deer populations (because of dams and irrigation agriculture) are resulting in increased predation by cougars on mule deer (apparent competition or alternate prey hypothesis). The apparent competition hypothesis predicts that as alternate prey (white-tailed deer) densities increase, so do densities of predators, resulting in increased incidental predation on sympatric native prey (mule deer). Apparent competition can result in population declines and even extirpation of native prey in some cases. Such a phenomenon may account for declines of mule deer in the IM and throughout arid and semi-arid West where irrigation agriculture is practiced. We will test the apparent competition hypothesis by conducting a controlled, replicated ''press'' experiment in at least 2 treatment and 2 control areas of the IM subbasins by reducing densities of white-tailed deer and observing any changes in cougar predation on mule deer. Deer densities will be monitored by WADFW personnel using annual aerial surveys and/or other trend indices. Predation rates and population growth rates of deer will be determined using radio telemetry. Changes in cougar functional (kills/unit time), aggregative (cougars/unit area), numerical (offspring/cougar), and total (predation rate) responses on deer will also be monitored using radio telemetry. The experiment will be conducted and completed over a period of 5 years. Results will be used to determine the cause and try to halt the mule deer population declines. Results will also guide deer mitigation and management in the IM and throughout the North American West.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 54

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Book Description
Construction of the Grand Coulee and Chief Joseph dams has resulted in inundation and loss of 29,125 total habitat units for mule deer and irrigation agriculture in many parts the Intermountain Province (IM) of the Columbia Basin. Mule deer in the Shrub-Steppe are ranked high priority target species for mitigation and management and are declining in most portions of the sub basins of the IM. Reasons for the decline are unknown but believed to be related to habitat changes resulting from dams and irrigation agriculture. White-tailed deer are believed to be increasing throughout the basin because of habitat changes brought about by the dams and irrigation agriculture. Recent research (1997-2000) in the NE IM and adjacent Canadian portions of the Columbia Basin (conducted by this author and funded by the Columbia Basin Fish & Wildlife Compensation Program B.C.), suggest that the increasing white-tailed deer populations (because of dams and irrigation agriculture) are resulting in increased predation by cougars on mule deer (apparent competition or alternate prey hypothesis). The apparent competition hypothesis predicts that as alternate prey (white-tailed deer) densities increase, so do densities of predators, resulting in increased incidental predation on sympatric native prey (mule deer). Apparent competition can result in population declines and even extirpation of native prey in some cases. Such a phenomenon may account for declines of mule deer in the IM and throughout arid and semi-arid West where irrigation agriculture is practiced. We will test the apparent competition hypothesis by conducting a controlled, replicated 'press' experiment in at least 2 treatment and 2 control areas of the IM sub basins by reducing densities of white-tailed deer and observing any changes in cougar predation on mule deer. Deer densities will be monitored by WADFW personnel using annual aerial surveys and/or other trend indices. Predation rates and population growth rates of deer will be determined using radio telemetry. Changes in cougar functional (kills/unit time), aggregative (cougars/unit area), numerical (offspring/cougar), and total (predation rate) responses on deer will also be monitored using radio telemetry. The experiment will be conducted and completed over a period of 5 years. Results will be used to determine the cause and try to halt the mule deer population declines. Results will also guide deer mitigation and management in the IM and throughout the North American West.

Author: Chad J. Bishop
Publisher:
ISBN:
Category : Mule deer
Languages : en
Pages : 32

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"Concerns over declining mule deer (Odocoileu hemionus) populations during the 1990s prompted research efforts to identify and understand key limiting factors of deer. Similar to past deer declines, a top priority of state wildlife agencies was to evaluate the relative importance of habitat and predation. We therefore evaluated the effect of enhanced nutrition of deer during winter and spring of fecundity and survival rates using a life table response experiment involving free-ranging mule deer on the Uncompahgre Plateau in southwest Colorado, USA"--page 1.

Author: Jacob H. Kay
Publisher:
ISBN:
Category :
Languages : en
Pages : 372

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Mule deer declined throughout the western United States over the last five decades. Researchers have identified numerous possible mechanisms underlying this range wide decline including: decrease in habitat quantity and quality, predation, competition with other species, disease and overharvest. However, changes in habitat conditions, resulting in diminished nutritional carrying capacity and predation have been the most widely implicated causes of declining mule deer populations. The relationships between nutrition, predation, climate and density dependence and their impact on mule deer vital rates are still not completely understood, and limit our ability to identify factors comtrolling population growth. However, as deer populations continue to decrease, managers face an increasingly urgent need to solve the complex ecological problems surrounding the decline of mule deer. I captured and fitted adult mountain lions (Puma concolor) and adult female mule deer (Odocoileus hemionus) with GPS telemetry collars and sampled vegetation in the Gallinas Mountains of New Mexico to examine the effects of predation and nutrition on mule deer.

Author:
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ISBN:
Category : Mammal populations
Languages : en
Pages : 150

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Author: Tavis Donahue Forrester
Publisher:
ISBN: 9781321608526
Category :
Languages : en
Pages :

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Mule (Odocoileus hemionus) and black-tailed deer (O. h. columbianus) have exhibited marked population fluctuations throughout their range over the past century. The relative contributions of predation, forage availability, and weather to observed population changes remain unclear and controversial. I evaluated the effects of both predation and forage on the survival of mule and black-tailed deer though a literature review and extensive field research in the Mendocino National Forest from 2009-2013. I reviewed 48 studies on mule deer survival and predation from the past 30 years and quantified age-specific vital rates, population growth rates (lamda) and causes of mortality. I also evaluated the effect of environmental variables on variation in vital rates and the contribution of age-specific survival to population growth. Age-specific survival (Phi) was the most frequently studied population parameter. Mule deer have lower and more variable fawn survival than other ungulate species (Phi(summer)=0.44, CV=0.42; Phi(annual)=0.29, CV=0.67). Adult female survival conversely appeared to be high and stable throughout the geographical range of the species (Phi(annual)=0.84, CV=0.06). Observed low fawn survival appears to be compensated for by high fecundity rates. Predation was the primary proximate cause of mortality for all age classes, and was an important source of summer fawn mortality and of mortality in multi-prey, multi-predator systems. However, predator removal studies suggest that predation is compensatory, particularly at high deer densities, and that nutrition and weather shape population dynamics. I propose three models to explain local population dynamics of mule deer: a) populations are limited by forage availability and weather; b) adult females are limited by forage availability, fawns are limited by forage availability and predation, and population growth is constrained by fecundity and fawn predation; and c) large changes in the abundance of predators or alternative prey change predation risk and destabilize population dynamics. From 2009 to 2013, I led field crews that captured and monitored 135 black-tailed deer fawns in coastal California to study possible interactions between forage and predation on survival. I estimated seasonal and annual survival rates, assessed the cause of all mortalities (n=95), measured available forage, estimated relative abundances of predators on summer range (i.e., fawning areas) each year, and used remote sensing to quantify habitat on winter range. I then used cumulative incidence and proportional hazards functions to evaluate how environmental covariates were related to fawn survival. Summer survival rates averaged 0.40 across all years (SE=0.05) and the mean annual survival rate was 0.25 (SE=0.04). I found that most fawn mortality resulted from predation during summer, mainly by black bears (Ursus americanus) and coyotes (Canis latrans), and spatial differences in summer survival persisted until recruitment. Black bear predation, the single largest cause of mortality, was unrelated to forage availability. Observed spatial variation in mortality risk due to other causes was linked to the availability of oak forage but not predator abundance. Additionally, characteristics of deer including adult female condition and fawn birthweight, did not provide evidence for purely bottom-up limitation. Rather my results provided evidence that both bottom-up and top-down effects were influencing fawn survival in this declining population, and that predator identity and the timing of mortality affected these interactions. I also tracked 57 adult female black-tailed deer using GPS collars and radio-telemetry to determine seasonal movements and home ranges and monitor survival and cause of mortality. I used the seasonal home range as a measure of site familiarity and modeled how mortality risk varied with use of familiar areas, forage availability, age class, and elevational overlap with simultaneously collared pumas using Cox proportional hazards models. Adult female survival was low in our study area (0.70 vs. 0.84 species average), and predation was the largest cause of mortality. The use of familiar areas was the best predictor of mortality risk, and deer that had a 40% chance of leaving the home range in a given week were 4 times more likely to die. Puma predation was the largest cause of mortality and deer whose average weekly elevation was farther from the average elevation of pumas were less likely to die. While forage availability was not related to mortality risk, adult females with lower forage availability were more likely to leave their home range in both summer and winter. I found fitness benefits of using familiar areas and bottom-up effects on the use of familiar areas as a refuge from predation. The benefits of site familiarity are likely widespread in ungulates, especially when there are stable home ranges, complex habitats, and unclear cues of predation risk. My results provide evidence that both bottom-up and top-down effects were influencing black-tailed deer survival in this declining population, and that predator identity, the timing of mortality, and individual behavior affected these interactions.

Author: James R. Heffelfinger
Publisher: CRC Press
ISBN: 1000851559
Category : Science
Languages : en
Pages : 537

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Black-tailed and mule deer represent one of the largest distributions of mammals in North America and are symbols of the wide-open American West. Each chapter in this book was authored by the world’s leading experts on that topic. Both editors, James R. Heffelfinger and Paul R. Krausman, are widely published in the popular and scientific press and recipients of the O. C. Wallmo Award, given every two years to a leading black-tailed and mule deer expert who has made significant contributions to the conservation of this species. In addition, Heffelfinger has chaired the Mule Deer Working Group sponsored by the Western Association of Fish and Wildlife Agencies for more than 15 years. This working group consists of the leading black-tailed and mule deer experts from each of 24 states, provinces, and territories in western North America, putting them at the forefront of all conservation and much of the research on this species. The book represents all current knowledge available on these deer, including how changing conditions such as fires, habitat alteration and loss, disease, climate change, socio-economic forces, energy development, and other aspects are influencing their distribution and abundance now and into the future. It takes a completely fresh look at all chapter topics. The revisions of distribution, taxonomy, evolution, behavior, and new and exciting work being done in deer nutrition, migration and movements, diseases, predation, and human dimensions are all assembled in this volume. This book will instantly become the foundation for the latest information and management strategies to be implemented on the ground by practitioners and to inform the public. Although this book is about deer, the topics discussed influence most terrestrial wildlife worldwide, and the basic concepts in many of the chapters are applicable to other species.

Author:
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Category :
Languages : en
Pages : 0

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Author: Kevin L. Monteith
Publisher:
ISBN:
Category : Mule deer
Languages : en
Pages : 56

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Vital rates of large herbivores normally respond to increased resource limitation by following a progressive sequence of effects on life-history characteristics from survival of young, age at first reproduction, reproduction of adults, to adult survival. Expected changes in life-history characteristics, however, should operate through changes in nutritional condition, which is the integrator of nutritional intake and demands represented primarily by the deposition and catabolism of body fat. Elucidating seasonal patterns of nutritional condition and its relative influence on individual and population performance should improve our understanding of life-history strategies and population regulation of ungulates, provide insight into the capacity of available habitat to support population growth, and allow assessment of the underlying consequences of mortality on population dynamics. We acquired longitudinal data on individual female mule deer (Odocoileus hemionus), and linked those data with environmental and population characteristics. Our goal was to provide a nutritional basis for understanding lifehistory strategies of these large mammals, and to aid in the conservation and management of large herbivores in general. We studied a migratory population of mule deer that overwintered in Round Valley on the east side of the Sierra Nevada, California, USA, and was subject to a highly variable climate and predation from a suite of large carnivores. We intensively monitored nutritional and life-history characteristics of this population during 1997-2009 as it recovered from a population crash, which occurred during 1985-1991. Deer in Round Valley migrated to high-elevation summer ranges on both sides of the crest of the Sierra Nevada (Sierra crest), where a rain shadow resulted in a mesic and more forested range on the west side compared with xeric conditions east of the Sierra crest. Average survival of neonatal mule deer to 140 days of age during 2006-2008 was 0.33 (SE1/40.091), but was lower for neonates on the west side (0.13, SE1/40.092) compared with those on the east side (0.44, SE1/40.11) of the Sierra crest. Birth mass and nutritional condition of mothers had a positive effect on survival of young; however, those effects were evident only for neonates born east of the crest where predation pressure was less intense compared with the west side. Black bear (Ursus americanus) predation was the main cause of mortality for west-side young (mortality rate1/40.63, SE1/40.97) compared with canid and felid predation for east-side young (0.29, SE1/40.076). Mean autumn recruitment of young during 1997-2008 was lower for females on the west side (0.42, SE1/40.037) than for females on the east side (0.70, SE1/40.041) of the crest, and was affected positively by March ingesta-free body fat (IFBFat) of individual females. At the level of the population, ratios of young-to-adult females (1991-2009) were highly variable and strongly related to March IFBFat of adult females during the current and preceding year. Reproduction by yearling females was sensitive to per capita availability of forage during summer (as 1-yr-old individuals), thereby influencing whether a sufficient body mass for ovulation was obtained. Litter size remained high (1.69, SE1/40.027) during the study, but was influenced positively by forage availability, negatively by summer temperature, and was greater for females that resided on the west side of the Sierra crest during summer than those on the east side. In contrast, pregnancy rates remained unchanged across years of study (0.98, SE1/40.005). Survival of prime-age (2- to 9-yr-old) females was 0.90 (SE1/40.021) in summer, 0.94 (SE1/40.012) in winter, and 0.87 (SE1/40.025) annually. Although relatively stable across years, both winter and summer survival were influenced positively by the preceding April snowpack relative to the density of the population. Mean IFBFat of adult females was 7.2% (SE1/40.077) in March 1997-2009 and 9.7% (SE1/40.23) in November 2002-2008. Nutritional condition offered a mechanistic link between factors that influence resource limitation and population performance, because condition of adult females in autumn and late winter was sensitive to the nutritional history of individual animals as related to forage growth, population density, migratory tactic, reproductive costs, and nutritional carryover. Nutritional condition of adult females in March also was the most parsimonious predictor of finite rate of population growth (l) during the forthcoming year. The relative magnitude of effect of nutritional condition on survival and reproduction was mostly in accordance with the predicted changes of vital rates in response to resource limitation for populations of large herbivores. Our results indicate that management and conservation of large herbivore populations could be improved by integrating indices of nutritional condition into current monitoring and research programs. We offer a method to estimate the proximity of a population to nutritional carrying capacity (NCC) that is based on nutritional status of the population relative to population performance (termed animal-indicated NCC). The proximity of the population to animal-indicated NCC represents the short-term capacity of the environment to support population growth. A nutritional approach to monitor and manage populations offers a direct link to the capacity of the habitat, and reduces the need to estimate population abundance or set goals according to population size. We also propose that the consequences of mortality (degree of additive or compensatory mortality) on population dynamics can be assessed by comparing the estimated nutritional capacity for survival and recruitment of young to that measured empirically, because more young are produced than what the habitat can support when nutrition is limiting. Our approach is useful for quantifying effects of predation, and provides a basis for determining the efficacy of predator control to enhance ungulate populations.