Download or read book Effects of Predation and Forage Availability on the Survival of Black tailed Deer Odocoileus Hemionus Columbianus in the Mendocino National Forest California written by Tavis Donahue Forrester and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Historic Survival Rates and Cause Specific Mortality for Columbian Black Tailed Deer in Southwest Oregon written by Kevyn A. Groot and published by . This book was released on 2015 with total page 93 pages. Available in PDF, EPUB and Kindle. Book excerpt: In contrast with other Odocoileus species, Columbian black-tailed deer (Odocoileus hemionus columbianus) population dynamics are not well understood throughout the species' range. Concerns over apparent long-term population declines have prompted efforts to fill basic knowledge gaps including estimates of vital rates (fecundity, recruitment and survival) and cause-specific mortality. The Oregon Department of Fish and Wildlife completed an extensive Columbian black-tailed (black-tailed) deer radio-collaring study in Oregon's south Cascade range from 1994 - 2000, with the goal of better understanding and anticipating the effects of different harvest management strategies on deer herds in the region. I utilized this historical data to conduct an in-depth investigation of seasonal sex- and age-specific survival rates and cause-specific mortality rates for marked black-tailed deer. I used known-fate data for 293 male and female radio-collared black-tailed of 3 age classes (yearling, 2-year old, adult) to estimate seasonal survival and investigate a variety of explanatory factors including sex, age class, temporal effects (seasonal, annual and trends across season and year), and time-dependent large-scale regional climate covariates. Variation in survival rates for this population was best explained by an interaction between sex and age class, with decreased probability of survival with increasing age class. The age effect was most pronounced in males, and although female survival in the older age classes was higher compared to male survival as predicted, yearling males had higher survival rates than yearling females. There was strong support for temporal variation in survival between summer and winter seasons, with winter survival best modeled as constant across years and summer survival variable across years. Winter survival was generally higher than summer except in 1997 when winter and summer rates were similar. Despite annual variation in summer survival rates, large-scale climate indices (Southern Oscillation Index, Pacific Decadal Oscillation, and Palmer Drought Severity Index) did not explain any temporal variation in survival rates within seasons. Low survival rates during the summer season, particularly for older males, resulted in low estimates of annual survival in some years. Annual estimates for males ranged from 0.47 - 0.76 for yearlings, 0.29 - 0.60 for 2-year olds and 0.14 - 0.40 for adults across the 6 years of this study. Annual estimates for females were generally higher than for males but were some of the lowest documented for the species, ranging from 0.47 - 0.76 for yearlings, 0.46 - 0.75 for 2-year olds and 0.44 - 0.74 for adults. I used the nonparametric cumulative incidence function estimator (NPCIFE) to generate annual and seasonal cumulative incidence functions for four competing risks: harvest, predation, other low-incidence sources of anthropogenic or natural mortality, and mortality due to unknown sources. Annual and seasonal risk functions were pooled across all years of the study to maximize sample size. As predicted in this system with limited antlerless harvest, cumulative risk of harvest across the entire annual cycle (365 days) was significantly higher for males (0.16, 95% CI = 0.11 - 0.21); a 16% annual cumulative risk compared to just 3% for females (0.03, 95% CI = 0.01 - 0.05). In addition, cause-specific mortality by male age class during the period of highest hunting pressure (general Cascade rifle season) suggested that 2-year-old males had over twice the cumulative risk of legal harvest with 22% of this age class killed by hunters during the general rifle season (0.22, 95% CI = 0.12 - 0.33) compared to 10% of adults (0.10, 95% CI = 0.04 - 0.15). Most yearling males survived the harvest season as cumulative legal harvest risk for yearling males was low (0.02, 95% CI = -0.01 - 0.06) relative to 2-year-olds and adults. Cougars (Puma concolor) were the primary predator of marked black-tailed deer and there was no significant difference in annual cumulative predation risk between the sexes (males: 0.05, 95% CI = 0.02 - 0.08; females: 0.05, 95% CI = 0.03 - 0.08), with only 5% risk of predation each year for both males and females. There was strong evidence that cumulative predation risk for females was higher in winter (0.04, 95% CI = 0.02 - 0.06) compared to summer (0.01, 95% CI = -0.002 - 0.02), and an increase in cumulative risk from February to May provides supportive evidence that females are more susceptible to predation during these months. High survival rates of yearling males with dramatic declines in survival once many of these deer became 2-year olds or older suggest that harvest may have had an additive effect and been the primary cause of low survival rates observed for males. Observed variability in summer survival resulted in variable, and in some years very low, annual survival rates for adult females; a strong contrast to the generally stable annual survival rates reported for other populations of mule deer. The highest estimates of annual survival for yearling males and for females of all age classes (0.74) in 1997 are comparable to the low range of estimates observed in other populations, but in other years estimates are much lower than what has been previously reported for black-tailed deer. These low survival rates might suggest a mechanism resulting in population decline over time, but more information on other vital rates (fecundity, fawn survival, and recruitment), carrying capacity of the system and population size is necessary to understand the population dynamics of black-tailed deer in this region during the 1990's. Properties of the data relative to male age classes in particular (low sample sizes, high censoring rates) decreased precision of these estimates and might have resulted in biased estimates. Adult females had consistently sufficient sample sizes over the course of the study to generate more precise, reliable estimates of survival, particularly in the latter 3 years of the study; these estimates should therefore be viewed with more confidence. Cause-specific mortality rates should be viewed as minimums due to the high number of unknown mortalities (40% of total) in the study population, but they suggest that hunting is the primary source of mortality for adult males and predation has the highest impact on seasonal female mortality rates. Given the historical nature of these results, my estimates should be used as a baseline and foundation for comparison with results from current black-tailed deer research in Oregon. These results have raised potential questions regarding harvest levels on male black-tailed deer in addition to possible resource constraints affecting both sexes on seasonal ranges, and can therefore focus new research to address these concerns.

Download or read book Distribution Patterns of Black tailed Deer Odocoileus Hemionus Columbianus in Relation to Environment written by F. L. Miller and published by . This book was released on 1965 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: Direct observation of a known number of black-tailed deer (Odocoileus hemionus columbianus), within the Cedar Creek study enclosure in the Tillamook Burn, Oregon, was carried on throughout 1964. Observations were made from three huts located outside of the enclosure on surrounding prominences. During this period, 1,410 hours of observational time yielded 6,746 sightings of deer. The distribution and activities of these deer were related to forage availability, plant communities, and climatic conditions. Extremes and sharp changes in temperature influenced deer activity. Deer became inactive when temperatures exceeded 60 degrees Fahrenheit. Both low temperature and sudden drops in temperature resulted in greatly reduced activity. Deer showed seasonal preferences for huckleberry-salal, big-leafed maple, and alder plant communities, while use of the vine maple community remained high throughout the year. The thimbleberry and bracken fern communities received relatively low use by deer. Plotted ratios of these preferences indicate winter survival value for deer in the juxtaposition of certain plant communities and a nonrandom distribution of deer. Seasonal distribution of deer was also influenced by elevation Deer sighted above 1,500 feet msl made up 84.7 percent of the total annual sightings. Seasonal peaks of daily activity were recorded as follows: midday peaks during January and February followed by early morning peaks during March, April, and May; slight late morning peaks and high twilight peaks in June through August; high early morning peaks and slighter twilight peaks in September; peaks in early morning and at midday with some revival at twilight in October; high activity throughout the day with a peak at midday in November; and high activity from mid-morning to twilight during December. Home range size was influenced by sex, age, available forage, water, cover, and prevailing weather. The largest annual home range was 312 horizontal acres and the smallest 86 horizontal acres. Size of monthly home ranges varied from 12.8 to 39.6 percent of the annual home range sizes. There was considerable variability in the distribution of deer among major land units.

Download or read book Ecology and Management of Black tailed and Mule Deer of North America written by James R. Heffelfinger and published by CRC Press. This book was released on 2023-04-27 with total page 537 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Using Foraging Dynamics to Answer Landscape Management Questions written by Amy Colleen Ulappa and published by . This book was released on 2015 with total page 165 pages. Available in PDF, EPUB and Kindle. Book excerpt: Black-tailed deer (Odocoileus hemionus columbianus) and other forest herbivores depend on abundant and nutritious understory vegetation found in open-canopy and young, early-seral forests. Forage management activities such as logging, thinning and using silvicultural herbicides have the potential to alter the quality and quantity of forage available to herbivores. Therefore, I compared nutrient intake and estimated nutritional carrying capacity of black-tailed deer between stands that received herbicide treatments paired with those that did not in Douglas-fir/western hemlock forests of western Washington, and investigated how these responses change as forests age from early seral stages to canopy closure (2 -- 20 years post-harvest). I measured understory vegetation biomass, plant species nutritional quality, and overstory characteristics of each forest stand. Additionally, I measured diet composition, diet quality and nutrient intake of tractable black-tailed deer within each paired stand. I found that herbicide use decreased the amount of understory biomass useable for foraging deer and decreased their daily digestible energy intake, especially in the first 3 years of stand establishment. Even so, early seral habitat, regardless of herbicide use, provided more forage and higher daily energy intake for deer than closed canopy stands (14 yrs +) or mid-seral stands. Using data from these experiments, I also investigated how the resolution of data collection (e.g., plants vs. plant parts) influences estimates of plant selection and nutritional carrying capacity, and how well measures of forage abundance and quality predict nutrient intake of black-tailed deer. I found that treating plant parts (i.e., stems and leaves) as separate food items did not influence how plant species were categorized as selected, neutral or avoided, but increased estimates of nutritional carrying capacity. In addition, measures of forage resources that included both biomass and quality or selection status by deer better predicted daily digestible energy intake of tractable black-tailed deer.

Download or read book Ecology of Columbian Black tailed Deer Fawns in Western Oregon written by Nathan P. Pamplin and published by . This book was released on 2003 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt: Little is known about Columbian black-tailed deer (Odocoileus hemionus columbianus) because of their elusive nature and the logistical difficulty of studying them in densely forested and mountainous terrain. The Oregon Department of Fish and Wildlife has identified fawn survival as an important gap in the current knowledge of demography and their understanding of an apparent population decline. We used vaginal-implant transmitters to locate birth sites and capture newborn Columbian black-tailed deer fawns in the Umpqua National Forest in western Oregon. We used modified Clover traps to capture deer during the winter and early spring of 2000 and 2001. Vaginal-implant transmitters were inserted into 36 adult does in 2000 and 32 adult does in 2001. We identified a total of 42 birth sites within our study area using this technique and we captured 23 fawns which we monitored daily throughout the summer. We modeled birth site selection by examining both site-specific variables and characteristics that describe habitat structure across a nested, hierarchical range of four circular areas. We used logistic regression to compare 42 birth sites with 80 random sites. The model that explained the most variation included the amount of edge and the average slope within 1,000 m of the birth site. We radiocollared 23 fawns from 2000 and 2001; 19 were captured at the birth site, which was identified using the vaginal-implant transmitter, and 4 were captured opportunistically. Fawns were located at least every other day and we assessed habitat selection using selection ratios. Fawns used open and shelterwood patches more than their availability in the study area. Timber habitats were used most by fawns, but were used less than available. Survival was monitored daily from the fawns estimated date of birth to 76 days. The Kaplan-Meier survival estimate for 76 days was 44% (95% confidence interval=23-66%). We fitted our survival data to the Weibull distribution and took an information-theoretic approach to construct a priori models using fawn capture morphometrics and habitat variables within a 600 m and 1,000 m radius of the capture site. The model that best explained fawn survival time was the amount of roads within a 1,000 m radius of the capture site. A higher road density within fawn summer range increases fawn survival time by likely minimizing predator density due to vehicular disturbance.

Download or read book Forest Habitats and the Nutritional Ecology of Sitka Black tailed Deer written by Thomas A. Hanley and published by . This book was released on 1989 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Relationships Between Sitka Black tailed Deer and Their Habitat written by Thomas A. Hanley and published by . This book was released on 1984 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Effect of Selenium on Reproduction of Black tailed Deer Odocoileus Hemionus Columbianus in Shasta County California written by Werner Thomas Flueck and published by . This book was released on 1989 with total page 612 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effect of Hair Loss Syndrome on Survival Behavior and Habitat Selection of Black tailed Deer Fawns written by Shannon L. Murphie and published by . This book was released on 2010 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Life history Characteristics of Mule Deer written by Kevin L. Monteith and published by . This book was released on 2014 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Effects of Predation on Black tailed Deer Population Growth written by Christian A. Smith and published by . This book was released on 1986 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Food Habits and Other Aspects of the Ecology of Black tailed Deer Odocoileus Hemionus Columbianus Near Hayward California written by Kwablah J-L. Attiogbe and published by . This book was released on 1979 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Food Habits of Black tailed Deer Odocoileus Hemionus Columbianus in Trinity County California written by and published by . This book was released on 1984 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Mule and Black tailed Deer of North America written by Olof C. Wallmo and published by . This book was released on 1981 with total page 632 pages. Available in PDF, EPUB and Kindle. Book excerpt: Developed in co-operation with U.S. Department of Agriculture, Forest Service.

Download or read book Nocturnal Activities of the Columbian Black tailed Deer Odocoileus Hemionus Columbianus Richardson Affecting Spotlight Census Results in the Oregon Coast Range written by Carl Frederick Anderson and published by . This book was released on 1959 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Social Dynamics of Black tailed Deer Odocoileus Hemionus Columbianus on the Staging Area During Spring Migration written by JoAnne Marie Smith and published by . This book was released on 1989 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt: