SPATIAL AND TEMPORAL PATTERNS IN WHITE-TAILED DEER FAWN SURVIVAL AND CAUSE-SPECIFIC MORTALITY.

SPATIAL AND TEMPORAL PATTERNS IN WHITE-TAILED DEER FAWN SURVIVAL AND CAUSE-SPECIFIC MORTALITY.
Author: Tess Gingery
Publisher:
Total Pages:
Release: 2018
Genre:
ISBN:

Juvenile survival may be the most critical component of large herbivore population growth, but how neonate survival changes over time and space is not fully understood. Neonate survival rates are influenced by maternal care, site-specific differences, and are generally characterized by year-to-year variation. Sources of white-tailed deer (Odocoileus virginianus) fawn mortality across North America include predation, natural causes (excluding predation), and both direct and indirect human-caused mortality. The relative frequency of these causes indicates which sources most affect neonate survival and can be easily compared among studies. We used a meta-analysis approach to elucidate spatial patterns in fawn survival at a landscape-scale across North America. However, comparing survival rates across time is not possible when confounded by spatial variation. Therefore, we investigated how fawn survival varied across time by conducting a neonate survival study in central Pennsylvania to compare a current estimate of neonate survival to previous estimates for central Pennsylvania in 20002001. Furthermore, because pre-weaned neonates (

Fawn Survival, Cause-specific Mortality, and Bed-site Selection of White-tailed Deer and Mule Deer in Western Kansas

Fawn Survival, Cause-specific Mortality, and Bed-site Selection of White-tailed Deer and Mule Deer in Western Kansas
Author: Mitchell J. Kern
Publisher:
Total Pages:
Release: 2019
Genre:
ISBN:

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.

Survival, Activity Patterns, Movements, Home Ranges and Resource Selection of Female Mule Deer and White-tailed Deer in Western Kansas

Survival, Activity Patterns, Movements, Home Ranges and Resource Selection of Female Mule Deer and White-tailed Deer in Western Kansas
Author: Talesha Karish
Publisher:
Total Pages: 0
Release: 2022
Genre:
ISBN:

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.

Examining how Spatial-temporal Interactions Between Predators Influence the Distribution, Vigilance, and Survival of White-tailed Deer (Odocoileus Virginianus) Fawns

Examining how Spatial-temporal Interactions Between Predators Influence the Distribution, Vigilance, and Survival of White-tailed Deer (Odocoileus Virginianus) Fawns
Author: Asia Murphy
Publisher:
Total Pages:
Release: 2021
Genre:
ISBN:

Predator-prey interactions are among one of the most important community-structuring interspecific relationships. It is well known that predators have direct (i.e., consumptive) effects (CEs), influencing population density [1] and survival [2, 3], and indirect (i.e., non-consumptive) effects (NCEs) on prey. Typically, NCEs are caused by the prey's antipredator behaviors, and can range from changes in distribution and habitat use [4-8] to changes in morphology [9] and decreased reproductive success and recruitment [10-13] to increased vigilance and group size [14, 15]. Based on their strength, CEs and NCEs can scale up to affecting entire ecosystems through trophic cascades [16, 17]. Antipredator behaviors are often tied to the prey's perception of predation risk, which is the probability of prey encountering a predator and/or being killed [7] and varies across space and time [18, 19]. Prey perception of predation risk is based on predator identity and hunting style [20-23], and prey often connect the risk of being killed by an ambush predator to specific habitat features [4], while the risk of being killed by a wide-ranging predator is often not tied to habitat features [17], although these types of predators might find more success in open habitats [24]. This suggests that prey will use different antipredator strategies to avoid different predators. Whereas prey might avoid risky habitats when avoiding ambush predators, prey might avoid being active and/or increase vigilance during risky hours when coursing predators might be active and hunting [25]. While many studies focus on the effect of a single predator on prey [i.e., 8], in most ecological communities, there are often multiple predators preying on the same species [26-28]. The number of predatory species in an ecological community can influence the strength of predator effects on prey [27, 29]. If the antipredator strategies that prey use to reduce predation risk by one predator indirectly increases its chance of being killed by another predator [i.e., predator faciliation; 30], predators can more effectively suppress prey populations [29, 31]. Prey in multi-predator systems often seem unable to completely avoid all predators, and instead focus their energies on using antipredator behaviors meant to avoid predators in order of lethality [32]. The interactions between predators, and the interactions between predators and humans, can also influence predation pressure on prey [33]. A comprehensive study on antipredator behavior and survival in a multi-predator system would determine not only the spatiotemporal distributions, antipredator behavior, and survival probability of the prey, but the spatiotemporal distributions of the predators. The white-tailed deer (Odocoileus virginianus) are culturally and economically important species across much of the United States [34] in Pennsylvania. The number one cause of mortality in white-tailed deer fawns is predation [3, 35]; in Pennsylvania, black bears (Ursus americanus), coyotes (Canis latrans), and bobcats (Lynx rufus; Vreeland et al. 2004, McLean et al. 2005) are all known to prey on fawns. All three predators use different habitats [37-39], can be active at different times [40-42], and have different hunting styles [43, 44], creating a landscape of predation risk that varies spatially and temporally [45]. In addition, these predators--particularly coyotes and bobcats [46-48]--can compete with and influence the habitat use and activity patterns of the other predators, further complicating the landscape that fawns must navigate to survive. While this landscape of multi-predator predation risk has been characterized before for white-tailed deer fawns [see 49, 50], no one has attempted to do so in Pennsylvania. In this dissertation, I examine how habitat relationships (Chapter 1) and spatiotemporal interactions of and between humans, fawns, black bears, coyotes, and bobcats influence the vigilance (Chapter 2) and survival (Chapter 3) of fawns during their first three months of life. In Chapter 1, I find that differing matrix types can influence the similarity of coyote and fawn habitat use. In Chapter 2, I posit that the risk allocation hypothesis can explain why a number of studies--including my own--have found that, in more anthropogenically disturbed habitats, species that would normally avoid spatiotemporal overlap with each other increase in spatiotemporal overlap. In Chapter 3, I estimate fawn survival, examine its relationship to fawn antipredator behavior and habitat, and find that data from camera trap surveys could be a feasible alternative to radio-collaring when the goal is to estimate fawn survival. My research provides new insights into species interactions are influenced by anthropogenic disturbance and a template for noninvasively and inexpensively examining these interactions.

Population Dynamics of White-tailed Deer on Tensas River National Wildlife Refuge, Louisiana

Population Dynamics of White-tailed Deer on Tensas River National Wildlife Refuge, Louisiana
Author: Rebecca Marie Shuman
Publisher:
Total Pages: 206
Release: 2016
Genre:
ISBN:

Survival of white-tailed deer (Odocoileus virginianus) fawns has declined in some areas of the southeastern U.S areas, and changing predator communities may complicate deer management scenarios. During 2013-15, I monitored survival of fawns and adult females on Tensas River National Wildlife Refuge (TRNWR), Louisiana. I determined cause-specific mortality and investigated variables influencing fawn survival. I used site-specific vital rates to model population trajectories and explored potential effects of changes in fawn and adult survival rates. Predation by black bear (Ursus americanus) was the greatest source of fawn mortality but appears to be partitioned with predation from other species. Fawn survival was positively correlated with birth mass and closer proximity to older reforestation sites but negatively correlated with proximity to young reforestation and cropland. Under current harvest guidelines and observed fawn survival rates, deer populations on TRNWR are sustainable, but reductions in female harvest could be considered if fawn survival decreases.

Biology and Management of White-tailed Deer

Biology and Management of White-tailed Deer
Author: David G. Hewitt
Publisher: CRC Press
Total Pages: 668
Release: 2011-06-24
Genre: Nature
ISBN: 1482295989

Winner of the Wildlife Society Outstanding Edited Book Award for 2013! Winner of the Texas Chapter of The Wildlife Society Outstanding Book Award for 2011! Winner of a CHOICE Outstanding Academic Title Award for 2011! Biology and Management of White-tailed Deer organizes and presents information on the most studied large mammal species in the world. The book covers the evolutionary history of the species, its anatomy, physiology, and nutrition, population dynamics, and ecology across its vast range (from central Canada through northern South America). The book then discusses the history of management of white-tailed deer, beginning with early Native Americans and progressing through management by Europeans and examining population lows in the early 1900s, restocking efforts through the mid 1900s, and recent, overabundant populations that are becoming difficult to manage in many areas. Features: Co-published with the Quality Deer Management Association Compiles valuable information for white-tailed deer enthusiasts, managers, and biologists Written by an authoritative author team from diverse backgrounds Integrates white-tailed deer biology and management into a single volume Provides a thorough treatment of white-tailed deer antler biology Includes downloadable resources with color images The backbone of many state wildlife management agencies' policies and a featured hunting species through much of their range, white-tailed deer are an important species ecologically, socially, and scientifically in most areas of North America. Highly adaptable and now living in close proximity to humans in many areas, white-tailed deer are both the face of nature and the source of conflict with motorists, home-owners, and agricultural producers. Capturing the diverse aspects of white-tailed deer research, Biology and Management of White-tailed Deer is a reflection of the resources invested in the study of the species’ effects on ecosystems, predator-prey dynamics, population regulation, foraging behavior, and browser physiology.