The Bearded Vulture, Gypaetus barbatus, was previously distributed across southern and western South Africa, as far south as Cape Town. Today, the entire population in southern Africa is restricted to the Lesotho highlands and the Drakensberg escarpment and nearby mountains in South Africa, where the population continues to decline. Research has shown that territorial abandonment is apparently associated with the density of human settlements within 10km of a territory. This pattern was assumed to be linked to the increased risk of unnatural mortalities in areas with higher human presence. However, habitat use and habitat selection, especially whether the species actively avoids human settlements has not yet been explored and could contribute to this pattern. In this study, we used data from nine adult Bearded Vultures fitted with Global Positioning System (GPS) satellite tags to determine which habitat is being selected. We modelled habitat selection in relation to various topographic and habitat variables, including information on built-up areas (i.e., areas with a high density of buildings). We predicted that birds would select areas of grassland and avoid areas with high building density and adjoining areas. We found that Bearded Vultures selected areas closer to their nest sites and supplementary feeding sites, with steeper slopes, and highly rugged terrain. In terms of habitat, they selected areas with grassland and avoided areas with forest, while cropland was neither selected nor avoided. As predicted Bearded Vultures avoided built-up areas and their vicinity. These results suggest that the Bearded Vulture may be sensitive to the negative impacts of a changing landscape in its distribution range. These results can help conservation managers in guiding development (e.g., human settlement expansion and afforestation) and protecting priority habitats (e.g., grassland) within the breeding range of adult Bearded Vultures.

The Hutchinsonian niche is the n dimensional hyper volume that allows for the persistence of a species. Castor canadensis, a large semi-aquatic rodent, is an ecosystem engineer and often a keystone species for many ecosystems. I examined the effect of multiple spatial scales on hierarchical habitat selection byC. canadensis using presence-only modeling techniques. I also determined individual trophic niche specialization in C. canadensis utilizing stable isotope analysis. I concluded that C. canadensis displayed scale independent habitat selection when comparing landscape and fine spatial scales. Individual trophic niche specialization occurred in colonies of the same resource availability. Also, individual trophic niches varied substantially between wetlands. These results have implications for the management of “generalist” species because populations can be composed of specialized individuals. Studies of niche across spatial and organizational scales are required for successful conservation and management strategies.

Spatiotemporal variation in animal space use is critical for understanding how individual animals respond to changes in resource availability across space and time. My study was aimed to: 1) determine functional responses of habitat selection by eastern wild turkeys (Meleagris gallopavo silvestris) across 7 study sites in Mississippi; and 2) determine the effect of temporal vegetation variation on order-II habitat selection by wild turkeys over 12 years. I developed resource selection functions using radio telemetry location data. Individual-specific coefficients of order-III habitat selection for forest were related inversely to forest availability in meta-regressions. Yearly coefficients of order-II habitat selection for forest were related inversely to the mean normalized difference vegetation index (NDVI) in April, but the coefficients for open fields were related positively to coefficient of variation in the NDVI from March to May. Wild turkeys exhibited functional responses of habitat selection to spatiotemporal forest availability across Mississippi.

With the advent of global position system (GPS) collar technology, we have developed a much greater understanding of the temporal and spatial distribution of livestock and their associated grazing patterns. While significant research using GPS collars has been reported for cattle, little research is available describing collar use in understanding the behavior of domestic sheep. The purpose of our research was to evaluate the energy requirements of sheep with the use of GPS collars. To accomplish this, we adapted a low-cost i-gotU GPS tracking device that is typically designed for cattle and modified it to fit sheep. Each collar was programmed to record sheep movements within four grazing habitat types during different times of the year. Habitat types included spring pasture (SP), spring low hill habitat (SH), summer mountain habitat (MH) and winter desert habitat (DH). We divided our research into two studies: 1) to track and compare energy expenditure of domestic sheep between four habitats using collars for recording sheep movements, and 2) to model summer mountain selection by sheep using the collar derived coordinate positions and environmental variables in an RSF model process. We hypothesized that there would more energy expended while out on desert habitat in comparison to other range habitats and sheep would select for sites on summer mountain habitat that were close to water, gentle in terrain, and higher in elevation. We used sheep energy equations to determine the energy requirement. Collar derived coordinates were used to measure the horizontal distance traveled on flat terrain or vertical distances both upslope and downhill across variable terrain. Our results found that total distance traveled was not different between SP, SH and MH at 6.7, 7.1 and 6.9 km/d, respectively, however, total movement was different (P<0.05) on DH at 10.5 km/d. Sheep movement was greater (P<0.05) on slopes (altitude change in 3m between waypoints) versus flat terrain (movement between waypoints >20m). For example, sheep spent 65% of movement on slope and 39% on flat movement for SH, 86% of movement was spent on slope and 16% on flat terrain for MH, and 89% of movement was spent on slope and 11% movement was on flat for DH. Total energy required between the four habitats was different (P<0.05) at 5.9, 8.6, 7.1 and 13.9 Mcal ME/d for SP, SH, MH and DH respectively. While on summer MH sheep avoided slopes and rugged terrain, but selected for sites close to water, northern facing aspects and areas higher in elevation. We found that sheep expend the most energy on DH and sheep on MH will select for gentle terrain, areas close to water, northern facing slopes, higher elevation and avoid slopes. With this insight, sheep managers can better meet energy requirements needs and understand habitat utilization of their flocks.

Research on northern bobwhite calling behavior and roosting ecology during the breeding season has received limited attention. However, variability in calling rate in response to conspecifics and environmental factors may affect avian monitoring strategies. We conducted 10-minute breeding season surveys (April-August) on B. Bryan Farms, Mississippi, from 2021-2022 to evaluate the impact of conspecifics and environmental covariates on male bobwhite calling rate. We observed a positive linear effect of conspecifics and temperature on calling rate. We did not find sufficient evidence to support a relationship between calling rate and cloud cover or barometric pressure. We also analyzed breeding season third-order roost site selection and found selection against bare ground and a quadratic relationship with litter and average vegetation height during roosting activity. It is also important for managers to consider all conditions of the environment and habitat requirements during every season for population persistence, including breeding season roost cover.

Mesocarnivores, including bobcats (Lynx rufus) and coyotes (Canis latrans), fill a unique ecological role throughout much of North America, where they were once influenced by larger predators, but are now the top predators where large carnivores have been extirpated. Their adaptability, generalist traits, and ability to coexist with humans to a greater extent than many species makes them an important subject for current predator research. In addition, their recent population recovery in the case of bobcats and historical range expansion in the case of coyotes make their study timely given a potential increase in their influence on their prey and environments. I investigated how bobcats and coyotes in southern and central Illinois respond in their spatial behavior to factors in their environment like human modification and resources, including a local pulsed resource, white-tailed deer (Odocoileus virginianus) fawns. These spatial behaviors include home-ranging behaviors, habitat selection, and movement, which can be extremely informative in estimating how mesocarnivores respond to landscape heterogeneity. I found that individual variation, which is understudied in much of current spatial research, played a powerful role in all of these behaviors. Bobcats and coyotes used different strategies to respond to human modification in their home ranges, with bobcats broadly expanding their home range with increases in human modification, and clearly selecting for or avoiding these features on the landscape. Meanwhile, coyotes did not expand their home ranges with human modification, but instead displayed temporal and spatial complexity in their functional responses to human modification. These differences in response revealed a gradient in spatial behaviors animals can use to exist in anthropogenic environments, influenced by a species’ behavioral plasticity. I also found that while bobcat and coyote targeting of fawns during fawns’ most vulnerable period was weakly supported at the population-level, there was a substantial amount of individual variation in fawn exploitation. These results provided evidence that there were some specialist individuals that may contribute much more to fawn predation than others, which was somewhat influenced by habitat type. Overall, I found important interspecies and interindividual variation in mesocarnivore spatial behaviors. My study demonstrates how mesocarnivores respond to habitat and prey resources and risks associated with human development. Using this information, I present a framework for predicting how species may respond to changes in their environments, as well as provide further insight into how mesocarnivores may affect ungulate recruitment.

Thesis (M.A.)--Humboldt State University, 2009. / Includes bibliographical references (leaves xi-xiv, following leaf 48). Also available via Humboldt Digital Scholar.

Thesis (Ph.D.) - University of St Andrews, May 2007.

Thesis (M.S.)--Oregon State University, 2007. / Printout. Includes bibliographical references (leaves 58-61). Also available on the World Wide Web.

Amphibian populations are declining globally due to a litany of factors including pollution, disease, climate change, and most importantly, habitat destruction. As most amphibian life histories involve their populations being recruitment limited, focusing on the mechanism behind breeding habitat selection will reveal useful cues that managers may use to increase abundance and breeding success. Though there are many theoretical models that describe the distribution of animals in response to a resource, the ideal free distribution (IFD) theory has not yet been applied to amphibian settling decisions. Through this application of the IFD, I have found that a population of wood frogs (Lithobates sylvaticus) in Patuxent National Wildlife Refuge select vernal pools that are large, deep, and hold water into the summer months to breed from 2010-2015. This information will provide managers with the ability to predict sites where wood frogs will breed in the future, as well as describe the cues that wood frogs are cueing in on so we can protect, alter, or create ideal breeding habitat.