Download or read book Survival Rates and Cause Specific Mortality of Mule Deer in South Central Oregon written by Elizabeth M. Mulligan and published by . This book was released on 2015 with total page 87 pages. Available in PDF, EPUB and Kindle. Book excerpt: It is critical for wildlife managers to understand the population dynamics of a harvested species, particularly for ungulates, which are a valuable wildlife resource. Due to concerns that mule deer (Odocoileus hemionus) populations in Oregon were declining, more comprehensive data on population vital rates and the factors potentially affecting them were needed by resource managers. To meet this research need, Oregon Department of Fish and Wildlife implemented a seven year study to investigate habitat use and survival of mule deer in eastern Oregon. From 2005-2012, the agency radiocollared 621 mule deer in south-central Oregon in order to gain more comprehensive information about seasonal movement, seasonal and annual survival, and changes in habitat use for the population. I used the radio-telemetry data from this larger study to investigate mule deer survival rates and cause-specific mortality and the effects of deer seasonal distributions, movement behavior, and environmental factors such as annual and climatic variation. I used known-fate data for 408 adult female radio-collared mule deer to estimate monthly survival rates and to investigate a variety of factors that might affect these rates including seasonal distribution, temporal effects (seasonal, annual, and trends across season and year), movement behavior, and climatic covariates on differing scales. Variation in survival rates for this population of female mule deer in eastern Oregon was best explained by an additive effect of migration behavior, fall migration period, and precipitation levels on individual winter ranges. Survival was significantly higher for migratory deer than residents. Both groups had lower survival during the fall migration period (Oct-Nov) and a positive linear relationship between survival and winter precipitation in individual winter ranges. Annual survival estimates for migrants ranged from 0.81-0.82, which is similar to other findings, but survival rates for residents (0.76- 0.77) were low in comparison to survival rates for adult female mule deer in other parts of their range. I used a nonparametric cumulative incidence function estimator (NPCIFE) to generate annual cumulative incidence functions separately for males and females due to differing risks associated with each sex. The four competing sources of mortality I included in this analysis for males were legal harvest, illegal harvest, predation, and starvation, disease, vehicle or fence-collision combined as one category (i.e., other). For females in investigated predation, human-associated mortality (vehicle or fence), illegal harvest, and natural causes (starvation and disease). Annual risk functions were pooled across all years of the study to maximize sample size. For males, the cumulative risk was highest for legal harvest (0.249, 95%CI=0.172-0.326), with predation the next highest cause of mortality for this sex (0.104, 95%CI=0.042-0.611). For females, the cumulative risk was highest for predation, (0.044, 95%CI=0.028-0.065) with anthropogenic causes (0.038, 95%CI=0.021-0.054) and illegal harvest (0.031, 95%CI=0.17-0.054) also important sources of mortality. Higher monthly survival rates of migrants compared to residents (across all months of the biological cycle) suggested that leaving for potentially higher quality summer foraging grounds outweighed the cost of traveling through unfamiliar habitats and energy expenditure from migration. Conversely, it may also imply that the summer ranges for residents had a negative effect on survival due to habitat quality or human disturbance. Both migrants and residents had lower monthly survival during the fall migration period (Oct - Nov). Female mule deer were excluded from the state-managed bow and rifle hunting season during this study, but females may experience the negative effects of human disturbance associated with fall hunting activities. This time of year is also energetically costly for females, being that some may still be nursing, which could have an additive effect to the energy used to migrate or avoid human disturbance. Winter precipitation also had positive effect on survival for both groups, possibly because increased average winter precipitation resulted in increased winter forage quantity and quality. My results suggest that female survival rates observed during my study are on the low end of the range reported for this species and may be contributing to population declines of mule deer in Oregon. Annual estimates of male survival were also low, but it is unclear how that might contribute to overall population declines without more information on annual and seasonal variation in male survival. Surprisingly, I observed high levels of illegal harvest on female deer and evidence that female survival during the fall migration period, which overlaps Oregon's legal harvest season, was lower than other times of the year. It is unclear why the fall migration period negatively affects both migrants and resident deer similarly, but future research should attempt to determine the specific factors that are negatively impacting mule deer survival during this time period in south-central Oregon. In addition, as human development in the area continues to grow, it is important to consider migration paths and the habitat quality of both summer and winter ranges. My results suggested that conditions may differ between summer ranges in particular, for residents vs. migrants, and understanding these differences may be the key to increasing survival of female mule deer in Oregon. Sharing information from this study with law enforcement and the general public may be the first step towards increasing awareness of, and thereby reducing, the relatively high levels of illegal harvest I documented for the female population. Future research should focus on investigating the differences in habitat quality for residents versus migrants, the factors that decrease survival during fall migration for both groups, and the social and economic factors that contribute to the illegal harvest of female mule deer in eastern Oregon.

Download or read book Assessment of Mule Deer Fawn Survival and Birth Site Habitat Attributes in South central Oregon written by David Speten and published by . This book was released on 2014 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mule deer (Odocoileus hemionus) populations in south-central Oregon are near their lowest levels since census efforts began in 1961. I investigated fawn survival, cause-specific mortality, and factors contributing to mortality from 2010 - 2012 to identify potential causes for the decline. I also explored pre-parturition and parturition site characteristics. I studied fawn survival among two different population segments in south-central Oregon. Adult females (n = 126;> 1 year old) were captured on winter ranges to collect biological samples and attach transmitters. Vaginal implant transmitters facilitated the capture of fawns (n = 127). Fawns (birth to

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 Survival Cause specific Mortality and Habitat Selection of Translocated Female Mule Deer in Southern New Mexico written by Jana Bethanie Ashling and published by . This book was released on 2015 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many mule deer (Odocoileus hemionus) populations in southern New Mexico have failed to recover from past population declines. Concurrently, populations near urban areas have increased, resulting in overabundant populations and increased human-wildlife conflicts, including damage to property and increased vehicle collisions. Rather than conducting large-scale, lethal removal of mule deer, a translocation program was initiated in an effort to simultaneously reduce the density of the urban mule deer population in Silver City, New Mexico, and augment low density populations in two local mountain ranges: the Peloncillo Mountains (PE) and San Francisco River Valley (SFRV) in southwestern New Mexico. I monitored survival and cause-specific mortality, and compared a hard versus soft release method in the second year to determine if release method influenced survival rates. Causes of mortality were predation (51%), disease (9%), accident (5%), and poaching (5%) with an additional 20% of mortalities due to unknown causes. Mountains lions (Puma concolor) caused most of the confirmed predator kills. Annual survival of translocated deer varied by year and location, but did not differ between release methods. In 2013-2014, annual survival in the PE of hard-released deer was 0.61 (SE = 0.10) compared to 0.26 (SE = 0.09) in the SFRV. In 2014-2015, survival of hard-released deer in the PE was 0.65 (SE = 0.16) and survival of soft-released deer was 0.77 (SE = 0.12). In the SFRV, survival of hard- and soft-released deer was 0.67 (SE = 0.15) and 0.49 (SE = 0.16), respectively. Results of my study demonstrate that translocation can be an effective management tool to augment populations of mule deer while reducing over abundant urban populations. It also aids in evaluation of release method, with my study showing that release method did not appear to affect survival. although the timeframe and conditions were limited.

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 Survival and Cause specific Mortality of Mule Deer Fawns Along the Upper Santa Fe Trail Northcentral New Mexico written by Laurie Araceli Lomas and published by . This book was released on 2006 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fawn Survival Cause specific Mortality and Bed site Selection of White tailed Deer and Mule Deer in Western Kansas written by Mitchell J. Kern and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Mule deer (Odocoileus hemionus) and white-tailed deer (O. virginianus) are common sympatric deer species in the Great Plains and western United States that have exhibited divergent population trends temporally and spatially. Mule deer populations are declining and contracting to the west while white-tailed deer populations are expanding. Species-specific differences in fawn recruitment is one proposed explanation for these observed trends, although the underlying causes remain unknown. To determine if landscape or other habitat changes are affecting the two deer species in different ways, we studied bed-site selection of mule deer and white-tailed deer fawns in western Kansas at microhabitat and landscape scales. We also assessed how fawn intrinsic factors, doe maternal condition, and bed-site habitat characteristics influenced survival of mule deer and white-tailed deer fawns. In February 2018 and 2019, we captured 120 adult does (60 mule deer, 60 white-tailed deer) using helicopter net-gun techniques and deployed 120 vaginal implant transmitters (VITs) synchronized with GPS collars deployed on does. Upon VIT expulsion, a birthing event notification was triggered, which narrowed search efforts for fawns. We captured and radio-collared 100 fawns (53 mule deer, 47 white-tailed deer) during 12 May- 23 June in 2018 and 2019. Fawns were visually located daily using ground-based radio-telemetry and we assessed bed-site selection, cause-specific mortality, and survival rates until fawns reached 10 weeks of age. Overall, fawn survival was low (0.32 ± 0.06) and did not differ between species (mule deer: 0.25 ± 0.08; white-tailed deer: 0.41 ± 0.08). Adult chest girth was positively associated with 70-day white-tailed deer fawn survival, longer fawn body length increased 7-day white-tailed deer fawn survival, and fawn sex best predicted 7-day mule deer fawn survival. Model uncertainty indicated fawn intrinsic factors and maternal conditions may be poor predictors of fawn survival. White-tailed deer survival was lower for fawns with more woodland in their home ranges and mule deer fawn survival exhibited a positive quadratic relationship with the amount of grassland within the home range. Mule deer fawn survival increased with the amount of edge and disaggregation within a home range, but landscape configuration did not explain survival of white-tailed deer fawns. We analyzed microhabitat characteristics at 2689 fawn bed-sites and 2689 paired random points. Bed-site selection differed by species; however, vegetative structure was the most influential microhabitat characteristic for both deer species. Mule deer fawns selected for 75% visual obstruction 8.4 dm tall, less grass cover, more succulent cover, and 56% shrub cover at bed-sites. White-tailed deer fawns selected for 25% visual obstruction 9.2 dm tall, 71% forest canopy cover, and less grass cover and bare-ground at bed-sites. The two species also showed differences in landscape selection. The odds of a white-tailed deer fawn bed-site increased 5.88 times in woodlands, whereas odds of a mule deer fawn bed-site increased 2.85 times in CRP. Our research suggests white-tailed deer fawns and mule deer fawns selected different characteristics for bed-sites at the microhabitat and landscape scale. Bed-site selection likely influences fawn survival, which could affect fawn recruitment. Managers should focus on maintaining heterogeneous landscapes composed mainly of native and Conservation Reserve Program grasslands with abundant cover to enhance mule deer fawn survival and bolster adult populations.

Download or read book Birth Site Selection and Neonate Survival of Mule Deer in the Blue Mountains of Oregon written by Danielle R. Walsh and published by . This book was released on 2016 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mule deer (Odecoilius hemionus) populations have been in decline in recent decades for a variety of reasons including habitat loss, disease, and competition. We were interested in what factors influence survival of neonatal mule deer in the Blue Mountains of Oregon. Individuals should select resources to increase fitness; therefore, females should select parturition sites with characteristics that have the potential to increase survival of their neonates. We examined what habitat characteristics females selected at birth sites as well as how those selected characteristics affected neonate survival. Additionally, we were interested in how changes in forage quality, maternal condition, climate, maternal age, and physical characteristics of neonates affected their survival. We conducted our research at Starkey Experimental Forest and Range in northeast, Oregon, primarily in the Main study area. We captured adult females during the winters of 2013-2014 and 2014-2015, and fitted them with GPS collars as well as inserting vaginally implanted transmitters. When parturition occurred in May and June, we located neonates and birth sites. Neonates were fitted with expandable collars so that we could monitor mortality. We measured metatarsus length, chest girth, and weight for adults and neonates. Additionally, we quantified body condition, measured maximum rump fat, and measured the jaw and body length of adults. At birth sites and 2 adjacent random sites, we measured overstory and hiding cover, the number of trees and shrubs, the distance to the nearest transition in vegetation type, and aspect. We determined selection of habitat characteristics at birth sites with resource selection functions using a mixed effects logistic regression. We chose our best model based on Akaike's Information Criterion corrected for small sample size. Our best model included significant parameters indicating selection for south facing slopes, increased overstory cover, and increased amounts of woody debris. We modeled neonate survival until weaning using the nest survival module in program MARK. We included different age trends to determine how survival changed. Survival from birth to weaning was 0.3169 (SE 0.706) and did not differ between years. Our best model indicated that survival changed daily from birth to day 30 and then began to stabilize and change weekly until weaning. Additionally our best model included a parameter for birth sites located on south facing slopes. Our results indicate that neonates born on south facing slopes have higher survival rates than those born in other locations. South facing slopes in this montane forested ecosystem are warmer and drier, providing a more stable microclimate for neonates who are born with few energy reserves. South facing slopes likely allow neonates to minimize energy use, which may increase their survival. Results from birth site selection analysis indicates that females selected habitat characteristics that increase hiding cover, potentially decreasing mortality by reducing predation events at birth sites. A better understanding of how deer select habitat characteristics to increase survival as well as what factors increase susceptibility to mortality allows for better management of populations. Management strategies that account for factors influencing survival will be better suited to counter population declines across the west.

Download or read book Survival Activity Patterns Movements Home Ranges and Resource Selection of Female Mule Deer and White tailed Deer in Western Kansas written by Talesha Karish and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: White-tailed deer (Odocoileus virginianus) and mule deer (O. hemionus) occur in sympatric populations across the Great Plains in North America. Mule deer abundance and occupied range has been declining during the past three decades while white-tailed deer abundance and occupied range has been increasing. Factors contributing to the dichotomous population growth and distribution patterns across their sympatric range are unknown, but potentially include differential survival, space use, and resource selection, all of which may be contributing to indirect competition that may be negatively affecting mule deer populations. Overlap in resource use or space use between mule deer and white-tailed deer could be evidence of competition or competitive exclusion. Activity patterns could provide insights for temporal segregation or competition. Differential space use could allow these species to spatially segregate and co-occur without competing for the same resources. My objectives were to 1) estimate annual and seasonal survival rates, 2) identify cause-specific mortality of adult female mule deer and white-tailed deer, 3) compare behavior patterns between adult mule deer and white-tailed deer of both sexes at seasonal and fine temporal period scales, 4) evaluate the difference in movements between adult female mule deer and white-tailed deer at seasonal and fine temporal scales, 5) test for differences in home range area and composition of adult female mule deer and white-tailed deer at seasonal and fine temporal scales, and 6) evaluate differences in seasonal multi-scale resource selection by female mule deer and white-tailed deer in western Kansas. I deployed collars on 184 pregnant females (94 mule deer and 90 white-tailed deer) at two different study sites in western Kansas (North, South) over three years, 2018, 2019 and 2020. Each deer received a high-resolution GPS/VHF collar that recorded hourly locations, activity accelerometer data along 3 axes, and used an activity sensor to identify mortality events. I used a Kaplan-Meier model to estimate cumulative weekly and annual survival and fit a hazard function to each survival model. I tested for relative influence of factors on estimated survival. I categorized activity points into three behavioral states (feeding, resting, and running). I converted activity points into a proportion of total behavior for each deer and tested for differences in the proportion of behavior categories between species and among seasons. I calculated individual hourly and daily movements seasonally and compared them between species and among seasons. I calculated annual and seasonal 95% home ranges and 50% core areas for each individual deer using a Biased Brownian Bridge movement model. Using logistic regression, I modeled resource selection by mule deer and white-tailed deer at the landscape scale, within home range scale, and within the core home range to identify selection for potential habitat variables and cover types. There was no difference in annual survival of adult female deer between species (mule deer [0.78 ± 0.04] and white-tailed deer [0.77 ± 0.05]). Harvest was the leading known cause of female mortality at 14% of the total mortality, but it was low compared to other studies in the Great Plains. Behavior of both species was similar in all seasons except for rut for males. In rut, males doubled their running behavior. Firearm season produced no changes in behavior for either species or sex. However, the greatest movements and home ranges were in the firearm season. There were greater movements and home ranges in the cold seasons than in the warm seasons. Mule deer were found to use steeper slopes than white-tailed deer, and white-tailed deer used riparian and woodland areas more than mule deer. Habitat patches enrolled in the U.S. Department of Agriculture Conservation Reserve Program were strongly selected by both species in every season and scale. Managers should focus on preserving CRP to stabilize the mule deer population. Given harvest rates of females are low, survival of adult females of both species of deer appears to be little affected by harvest, so there is no need to alter harvest rates of either species.

Download or read book Survival of Neonate Mule Deer Fawns in Southern Utah written by Jacob Tyler Hall and published by . This book was released on 2018 with total page 61 pages. Available in PDF, EPUB and Kindle. Book excerpt: Second, we examined how synchrony of parturition affects the survival and cause-specific mortality of neonate mule deer. Reproductive synchrony is a strategy that influences the survival of juveniles and the growth of populations. Our objective was to test three possible explanations for the synchrony of parturition in mule deer; 1) pressure of predation on newborns, 2) a hybrid of predation and environmental effects, and 3) weather and food availability. To determine the effects of the timing of parturition on the survival and predator-related mortality of neonate mule deer, we used multi-model inference within Program MARK and a known-fate model. Our results indicated that the timing of parturition influenced survival and predator-related mortality of neonate mule deer. There was a lag between the onset of parturition of mule deer and predation of mule deer by fawns; individuals born close to the onset of parturition had higher survival and lower predator-related mortality than those whose births were delayed relative to the onset of parturition. Since predators selected for neonate mule deer that were born late, predator learning may partially explain reproductive synchrony in mule deer. Environmental factors may have a greater effect than predation on the survival of early-born individuals.

Download or read book Approaches to Field Investigations of Cause specific Mortality in Mule Deer written by Kourtney Faith Stonehouse and published by . This book was released on 2016 with total page 65 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effect of Enhanced Nutrition on Mule Deer Population Rate of Change written by Chad J. Bishop and published by . This book was released on 2009 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: "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.

Download or read book Mule Deer Occupancy of Plant Communities on a South Central Oregon Winter Range written by Donavin A. Leckenby and published by . This book was released on 1976 with total page 77 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Use of Mule Deer Highway Mortality and Migration Data to Prioritize Wildlife Passage Structures on 2 Highways in Central Oregon written by Jacqueline B. Cupples and published by . This book was released on 2014 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Response of Forage Species Seeded for Mule Deer in Western Juniper Types of South central Oregon written by D. A. Leckenby and published by . This book was released on 1983 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 A Test of the Southcentral Oregon Mule Deer Habitat Suitability Index Model written by Donald Gay and published by . This book was released on 1998 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt: