Wildlife management

Animal migration is defined as the seasonal movement from one independent and non-overlapping range to another. Understanding how and why animals migrate is important not only to understand their life history processes but also for informing other important ecological processes such as the spread of wildlife disease and habitat alteration. Animal migrations have been impacted by human activity with instances of complete loss of migrations in human-altered areas. Understanding the drivers of migration can help predict responses to future environmental changes and potentially help conserve these phenomena. Seasonal movements of white-tailed deer (deer; Odocoileus virginianus; Zimmerman, 1780) have been linked to seasonal changes in environmental conditions that impact their ability to find food resources and risk of predation. The human shield hypothesis posits that prey species will select habitat close to people to use predator fear of humans to protect themselves from predation. Using global positioning system (GPS) collars, we examined the onset of deer migrations and assessed how environmental variables including snow, temperature, and plant biomass influenced migration departure dates using time-to-event models. We compared deer locations to data from GPS collared coyotes (Canis latrans; Say, 1823) within the same study area to explore daily space-use differences and examine if deer migrations were food or predation-risk driven using generalized linear mixed effects regression models. We found substantial annual and individual variation in deer migration dates. Snow depth was the strongest and most consistent predictor of deer migration, with individuals departing earlier with greater snow depth. Our regression analyses showed that deer selected for habitats closer to and with greater density of anthropogenic structures than coyotes at all times. After removing the animal locations close to areas with active supplemental feeding, these effects were diminished showing no differences in proximity or density of structures. Overall, we found more support for a food driven migration rather than a predator driven human shield. With the reduction in natural food caused by snow cover, we suggest that supplemental feeding is likely influencing the use of wintering areas by deer. The high proportion of deer migrating to human developed areas with supplemental feeders highlights the need for continued research into the impacts of human activity on animal behaviour.

Author Keywords: coyote, human shield, migration, supplemental feeding, white-tailed deer

Muskrat populations are declining across North America. In recent decades, hybrid cattail Typha x glauca has been invading wetlands in North America. This invasion is degrading wetland habitat, leading to reduced interspersion of water and vegetation. Muskrats are wetland-obligates and their populations are positively linked to marsh interspersion. Therefore, muskrat populations may be declining due to the invasion of T. x glauca and subsequent reduction in interspersion. To test this hypothesis, I first sampled marshes across south-central Ontario, comparing muskrat densities with the relative frequency of T. x glauca and the degree of interspersion. Second, I measured intensity of use by muskrats in a large wetland along a gradient of interspersion. My findings suggest that reduced interspersion may be contributing to muskrat population declines, but it is unclear to what degree T. x glauca is responsible. Further research is needed to understand the effects of wetland invasions on muskrat populations.

Author Keywords: invasive species, Ondatra zibethicus, Southern Ontario, Typha x glauca, wetlands, wildlife conservation

Understanding habitat needs of a species is critical, especially for species reintroduced to an area or expanding their range. I evaluated roost tree selection and survival probability of GPS-tagged eastern wild turkeys (Meleagris gallopavo silvestris) from 2017–2020 and 2022 in Peterborough County, Ontario, Canada. Fine-scale roost tree selection was associated with larger trees, with microclimate factors such as wind speed, temperature, and precipitation having little to no influence. Turkeys showed high annual survival probabilities relative to other northern regions of their range, but survival was not influenced by proximity of roost tree to a building. The behaviour of roosting in an elevated perch helps turkeys avoid ground-dwelling predators, but specific selection of one tree versus another has little additional benefit to survival. Turkeys appear to survive well in a landscape that is a mix of agricultural and urban, with forest patches intact for roosting habitat.

Author Keywords: Eastern wild turkey, habitat, Meleagris gallopavo silvestris, microclimate, roost sites, survival

Arctic breeding shorebirds are often considered alternate or secondary prey to avian and terrestrial predators that primarily feed on cyclic populations of rodents. Predation risk can strongly influence habitat selection; however, there is limited understanding of how nest placement by shorebirds and subsequent risk of nest predation are affected by spatiotemporal patterns involving the indirect effects of alternate prey on predator activity. I examined nest fates of Whimbrel (Numenius phaeopus) and Dunlin (Calidris alpina) at the southernmost edge of their breeding ranges at Polar Bear Provincial Park, Ontario, using field surveys including direct observations, camera monitors and thermal probes. I used resource selection functions (RSFs) to compare used and available habitat features near shorebird nests. I assessed whether shorebird nest predation was affected by spatial patterns in avian predator activity, habitat, and small mammal alternate prey and annual variation in cyclic small mammal abundance. RSFs confirmed strong habitat selection for graminoid fen habitats with avoidance of tundra heath, presumably to avoid terrestrial predators that may use them as travel corridors. Shorebird nest predation was not affected by the spatial variation in avian predator activity. However, Dunlin nest predation risk was affected by spatial variation in small mammal abundance. Further, the effect was strongest in years consistent with peaks in the small mammal population cycle. These findings highlight the important effects of spatiotemporal variation of alternate prey densities on Arctic-Subarctic food webs, providing insights on the complex relationships affecting shorebird nest success.

Author Keywords: apparent competetion, Dunlin, Empirical Bayesian Kriging, Shorebird, Subarctic, Whimbrel

Trait variation in wild populations is shaped by the interaction of genetics and the environment. Given these interactions, this thesis explored trait variation in white-tailed deer from two angles: one focused on broad-scale environmental factors, the other on fine-scale genetic mechanisms. The first chapter investigated how climate and habitat variation influence antler size, morphology, and the distribution of record-scoring deer across Ontario, Canada. Our results showed that warmer temperatures and higher percentages of rangeland and forest landcover were linked to larger antlers, while harsher winters with more precipitation had negative effects. The second chapter described the development of novel SNP assays designed to target genetic markers associated with leucism and malocclusions in an isolated island population of white-tailed deer. Together, these results highlight the importance of considering both environmental and genetic factors to understand trait variation in white-tailed deer.

Author Keywords: antlers, Odocoileus virginianus, phenotypic variation, Runs of homozygosity, white-tailed deer

Quantifying the impacts of environmental conditions on the abundance of wildlife populations is important for making informed management decisions in the face of increasing environmental threats. Managers require robust tools to estimate abundance and density of wildlife rapidly and with precision. Within the context of studying white-tailed deer, I evaluated the use of camera-traps and a recently developed spatial-mark resight model to estimate deer density and evaluate habitat and land use factors influencing deer density. The study was conducted in central Ontario, Canada on approximately 16 km2 of public land including the protected Peterborough Crown Game Preserve. Telemetry locations from 39 radio-collared deer were used and one hundred camera-traps were deployed for a total of 140 days from January 2022 to May 2022. Using telemetry locations and camera-trap photos I built a two-step spatial-mark resight model to estimate deer density. Deer density varied during the study as a portion of the population migrated to wintering areas outside of the study area. Despite fluctuations in precision, estimates improved towards the end of the study as more data became available and deer space use stabilized. The average deer density during the entire study was 3.0 deer/km2 (95% CI= 0.1, 5.8; SD= 1.7; CV= 55%; N= 238 deer). The lowest mean density was 0.2 deer/km2 (95% CI= 0.1, 0.4; SD= 0.1; CV= 50%; N= 15 deer) from February 26th to March 11th and the highest mean density was 4.8 deer/km2 (95% CI= 3.1, 6.2; SD= 0.8; CV= 17%; N= 378 deer) from May 7th to May 20th. When I incorporated spatial covariates into the model to estimate effects on deer density, higher proportions of mixed forest, deciduous forest, and road and trail density all had negative effects on deer density. While models contained some uncertainty, deer density appeared higher in the portion of the study area protected from licensed hunting. This thesis provides a framework for managers to use camera-traps and the spatial-mark resight model to monitor deer populations and link environmental covariates to spatial variation in density. As environmental threats such as habitat loss and infectious diseases increase in severity, monitoring wildlife population numbers will be vital for informed responses to these threats. The two-step spatial-mark resight model with environmental covariates provides managers with a long-term monitoring tool to evaluate management efforts and population health in forested areas.

Author Keywords: camera-trap, chronic wasting disease, landscape ecology, spatial-capture recapture, white-tailed deer, wildlife management

Wildlife translocation programs are widely employed as a strategy to reintroduce extirpated species into regions they once inhabited but no longer do. Reintroduction programs can be successful at re-establishing extirpated populations and also provide unique opportunities to study post-reintroduction population dynamics and behavioural ecology. The wild turkey (Meleagris gallopavo) is a forest generalist species that, prior to European colonization, inhabited much of the Carolinian zone in Ontario. This species was hunted to extirpation in the early 1900's and reintroduced in the mid-1980's through a series of wildlife trade agreements and coordinated trap and transfer efforts. Ontario's contemporary populations are seemingly thriving, with wild turkey harvest permitted in many regions of the province. However, given this species history of extirpation, understanding the size, distribution, and behavioural ecology of Ontario's reintroduced population of wild turkeys is essential to their long-term persistence in the province. We captured and radio-tagged 77 wild turkeys over four years in Peterborough, Ontario and studied their movement, sociality, and habitat preferences. My findings indicate that Ontario may contain relatively high densities of this species when compared with other parts of their range. My analyses also elucidated interesting aspects of this species habitat selection patterns within an anthropogenic landscape, in addition to novel findings surrounding wild turkey sociality and genetic structure.

Author Keywords: behaviour, genetics, Ontario, reintroduction, wild turkey, wildlife management

Animal migration is defined as the seasonal movement from one independent and non-overlapping range to another. Understanding how and why animals migrate is important not only to understand their life history processes but also for informing other important ecological processes such as the spread of wildlife disease and habitat alteration. Animal migrations have been impacted by human activity with instances of complete loss of migrations in human-altered areas. Understanding the drivers of migration can help predict responses to future environmental changes and potentially help conserve these phenomena. Seasonal movements of white-tailed deer (deer; Odocoileus virginianus; Zimmerman, 1780) have been linked to seasonal changes in environmental conditions that impact their ability to find food resources and risk of predation. The human shield hypothesis posits that prey species will select habitat close to people to use predator fear of humans to protect themselves from predation. Using global positioning system (GPS) collars, we examined the onset of deer migrations and assessed how environmental variables including snow, temperature, and plant biomass influenced migration departure dates using time-to-event models. We compared deer locations to data from GPS collared coyotes (Canis latrans; Say, 1823) within the same study area to explore daily space-use differences and examine if deer migrations were food or predation-risk driven using generalized linear mixed effects regression models. We found substantial annual and individual variation in deer migration dates. Snow depth was the strongest and most consistent predictor of deer migration, with individuals departing earlier with greater snow depth. Our regression analyses showed that deer selected for habitats closer to and with greater density of anthropogenic structures than coyotes at all times. After removing the animal locations close to areas with active supplemental feeding, these effects were diminished showing no differences in proximity or density of structures. Overall, we found more support for a food driven migration rather than a predator driven human shield. With the reduction in natural food caused by snow cover, we suggest that supplemental feeding is likely influencing the use of wintering areas by deer. The high proportion of deer migrating to human developed areas with supplemental feeders highlights the need for continued research into the impacts of human activity on animal behaviour.

Author Keywords: coyote, human shield, migration, supplemental feeding, white-tailed deer

Muskrat populations are declining across North America. In recent decades, hybrid cattail Typha x glauca has been invading wetlands in North America. This invasion is degrading wetland habitat, leading to reduced interspersion of water and vegetation. Muskrats are wetland-obligates and their populations are positively linked to marsh interspersion. Therefore, muskrat populations may be declining due to the invasion of T. x glauca and subsequent reduction in interspersion. To test this hypothesis, I first sampled marshes across south-central Ontario, comparing muskrat densities with the relative frequency of T. x glauca and the degree of interspersion. Second, I measured intensity of use by muskrats in a large wetland along a gradient of interspersion. My findings suggest that reduced interspersion may be contributing to muskrat population declines, but it is unclear to what degree T. x glauca is responsible. Further research is needed to understand the effects of wetland invasions on muskrat populations.

Author Keywords: invasive species, Ondatra zibethicus, Southern Ontario, Typha x glauca, wetlands, wildlife conservation

Quantifying the impacts of environmental conditions on the abundance of wildlife populations is important for making informed management decisions in the face of increasing environmental threats. Managers require robust tools to estimate abundance and density of wildlife rapidly and with precision. Within the context of studying white-tailed deer, I evaluated the use of camera-traps and a recently developed spatial-mark resight model to estimate deer density and evaluate habitat and land use factors influencing deer density. The study was conducted in central Ontario, Canada on approximately 16 km2 of public land including the protected Peterborough Crown Game Preserve. Telemetry locations from 39 radio-collared deer were used and one hundred camera-traps were deployed for a total of 140 days from January 2022 to May 2022. Using telemetry locations and camera-trap photos I built a two-step spatial-mark resight model to estimate deer density. Deer density varied during the study as a portion of the population migrated to wintering areas outside of the study area. Despite fluctuations in precision, estimates improved towards the end of the study as more data became available and deer space use stabilized. The average deer density during the entire study was 3.0 deer/km2 (95% CI= 0.1, 5.8; SD= 1.7; CV= 55%; N= 238 deer). The lowest mean density was 0.2 deer/km2 (95% CI= 0.1, 0.4; SD= 0.1; CV= 50%; N= 15 deer) from February 26th to March 11th and the highest mean density was 4.8 deer/km2 (95% CI= 3.1, 6.2; SD= 0.8; CV= 17%; N= 378 deer) from May 7th to May 20th. When I incorporated spatial covariates into the model to estimate effects on deer density, higher proportions of mixed forest, deciduous forest, and road and trail density all had negative effects on deer density. While models contained some uncertainty, deer density appeared higher in the portion of the study area protected from licensed hunting. This thesis provides a framework for managers to use camera-traps and the spatial-mark resight model to monitor deer populations and link environmental covariates to spatial variation in density. As environmental threats such as habitat loss and infectious diseases increase in severity, monitoring wildlife population numbers will be vital for informed responses to these threats. The two-step spatial-mark resight model with environmental covariates provides managers with a long-term monitoring tool to evaluate management efforts and population health in forested areas.

Author Keywords: camera-trap, chronic wasting disease, landscape ecology, spatial-capture recapture, white-tailed deer, wildlife management