The Slate Islands caribou (Rangifer tarandis caribou) is an insular population which has experienced several population crashes and has been described as likely to succumb to extirpation. While a great deal of research has been conducted on mainland woodland caribou, factors which influence caribou distributions may differ between island and main land populations. In this thesis, I investigate relationships between habitat, landscape, anthropogenic features, population size, predation and spatial distribution of woodland caribou across the Slate Islands Provincial Park (Ontario) at the forest-patch spatial scale. Generalized linear models were used to compare observed caribou locations to available locations across the park, based on data from 1978 to 1995. Results indicated that the Slate Islands caribou selected deciduous cover, larger forest patches, areas further to water, flatter areas, lower elevations and areas closer to anthropogenic features. Population size had a limited effect on caribou distributions. / October 2015

Individual-level life-history strategies are the rails that guide population dynamics. Due to the difficulty of conducting long-term, individual-based studies, current management practices often focus on estimating and controlling demographic rates with little consideration for the individual-level responses that guide them. This approach cannot account for important factors such as age-specific responses to changes in population density or long-term impacts of conspecific density and resource limitation. As such, population-level approaches may fail to predict age structure or the rate of population growth. Recent studies of mammals and birds have shown that short-term changes in factors such as population density can have lasting impacts on vital rates of individuals. These results highlight the importance of long-term individual-based analyses in understanding population dynamics. However, very few researchers have thus far been able to isolate and study interacting effects of density and resources on life histories apart from processes such as predation, interspecific competition, and management of anthropogenic disturbance. The feral horses (Equus ferus caballus) of Sable Island, Nova Scotia, Canada, exist in a natural though simplified system without predation, human interference, or interspecific competition (they are the island’s only terrestrial mammal, numbering approximately 500 individuals). Here I determined the roles of local conspecific density and an interacting resource gradient in guiding the reproduction and survival of adult female Sable Island horses (2008–2012). I used body condition (estimates of subcutaneous fat) as an indication of resource allocation towards the often conflicting purposes of reproduction and maintenance. Reproduction was best predicted by body condition (reproducing females were in relatively poorer condition) but there was also evidence of density-dependence in reproductive success. Survival was predicted by and positively related to body condition. Survival was also predicted by an interaction between conspecific density and location on the island consistent with expectations of a known east-west resource gradient that occurs on Sable Island (in available water and forage). Greater variability in fitness estimates in resource-poor, eastern Sable Island suggests that regions of low density and resources may be high risk/high reward habitats. Such habitats may be disproportionately avoided by young animals and exploited by senescent animals. All feral horses are descended from domesticated animals and recent work has found evidence of artificially selected life-history traits in unmanaged populations of domestic mammals like cattle, sheep, and horses (e.g., reproducing even at high densities and earlier in life than expected). I therefore attempted to determine if effects of artificial selection existed in the Sable Island population by examining age-based contributions to population growth and the relationship between reproduction (foaling) and female mortality. Perhaps due to the population’s long history of low management (>250 years), I failed to find any strong evidence of artificially selected life-history traits in Sable Island horses. That is, life history trade-offs in survival and reproduction in Sable Island horses were more similar to wild species of large herbivores inhabiting natural environments, than other populations of feral ungulates. My research suggests a rarely documented but fascinating instance of reversal of artificial selection by natural selection for a domesticated species like the horse.

Ontogenetic niche shifts generally coincide with changes in size, morphology, behavior, and/or feeding preferences during development, resulting in a shift in preferred habitat. In aquatic species, these ontogenetic niche shifts are often associated with habitat-dependent changes in competition and/or predation dynamics, expressed as a size-depth relationship where the larger-bodied adults occupy deeper habitats while the smaller-bodied juveniles primarily reside in shallower regions. While the influence of interspecific interactions on size-structured habitat occupancy has been well studied, few have examined the potential role of intraspecific agonistic interactions between size classes in ontogenetic niche shifts. A simulation model was developed to test whether the size-specific habitat occupancy observed in signal crayfish can be explained by the size-structured individual responses to agonistic interaction, where the smaller-bodied juvenile responds to the interaction with an escape movement, to avoid engagement and the risk of mortality or injury from the adult. The simulated movements of signal crayfish resulted in higher juvenile occupancy of riffles relative to pools reflecting a greater rate of escape from adults into riffles, away from the higher densities of adults in their preferred habitat (i.e. pools). This provides evidence that the juvenile escape response to size-structured, intraspecific, agonistic interactions may contribute to ontogenetic niche shifts.

No description available.

No description available.

An understanding of the adaptability of belugas (Delphinapterus leucas) to changing ice-conditions is required to interpret and predict possible changes in habitat selection in response to projected loss of sea ice throughout the circumpolar Arctic. Beluga spring distribution in the eastern Beaufort Sea was described by analyzing observations from aerial surveys conducted from 1975 to 1979. Repeated surveys along the Franklin Bay fast-ice edge in June 2008 were used to study the distribution and behaviour of belugas and bowheads. Despite inter-annual variability in ice extent, belugas consistently selected areas with water depths of 200-500 m, heavy ice concentrations (8/10 to 10/10) and seafloor slope ≥0.5 degrees in spring 1975 to 1979. While predator avoidance may partially explain the observed distribution, foraging success likely has more influence on beluga habitat selection in the spring. In ice-covered offshore regions, belugas may be engaged in under-ice and deep water foraging on Arctic cod (Boreogadus saida). In lighter ice years, belugas may expand their distribution and shift shoreward to take advantage of high prey densities along fast-ice edges. Both belugas and bowheads appeared to be feeding along the Franklin Bay ice edge in June 2008. More research is required to examine and compare possible changes in distribution since the late 1970s and to investigate the factors driving the patterns described.

Successful forest management requires an understanding of the habitat requirements of individual species at multiple spatial scales. The cerulean warbler (Dendroica cerulea) is a neotropical migratory songbird that has recently gained widespread attention as a species of conservation and management concern. It breeds in mature, deciduous forests of eastern North America and has experienced precipitous range-wide declines over the last 40 years. Although Kentucky likely supports one of the largest breeding populations of the species, no information exists on cerulean warbler habitat selection within the state. The overall purpose of this study was to identify important habitat features associated with cerulean warbler distribution on breeding grounds in eastern Kentucky. In 2004 and 2005, I examined cerulean warbler distribution and associated vegetative characteristics within a hierarchical framework at the stand, territory, and nest-site levels. I used the Information-Theoretic approach to develop 2 sets of a priori models. The first set of models attempted to explain cerulean warbler site occupancy through presence and absence data obtained from point counts. The second set of models attempted to explain differences between preferred song perches and available habitat. Due to small sample size, nest-site information was not used in modeling efforts. Results from presence and absence modeling were inconclusive as no habitat-related differences were identified between occupied and unoccupied locations within the study area. However, territory modeling revealed three potentially important predictors of cerulean warbler habitat: large diameter trees, east-facing aspect, and increased shrub cover. This study reinforces general patterns observed throughout the cerulean warblers breeding range. Although the mechanisms causing cerulean warbler declines are still poorly understood, conservation and management efforts directed toward protecting and establishing large tracts of mature forest with large trees on mesic, sheltered sites should be a reasonable approach to managing cerulean warbler populations on the breeding grounds.

According to theory, habitat selection by organisms should reflect the associated probability of survival or reproductive success. Understanding habitat selection, at multiple scales, is of interest not only from a theoretical perspective, but from an applied perspective for species conservation. Northern pintails (Anas acuta) are migratory, temperate-nesting birds that breed in greatest concentrations in the prairies of North America. Declining populations suggest that habitat loss and changing land use may have decoupled formerly reliable fitness cues from selection of suitable nest habitat. I used data from 62 waterfowl nesting study sites in prairie Canada (1997–2009), to examine whether nest survival, a primary fitness metric, at nest and habitat patch scales, was predictive of habitat selection at corresponding scales. In addition, I used systematic long-term annual pintail population monitoring data (1961–2009), and recruitment indices (juvenile:adult female ratio) from hunter harvest, to examine adaptive habitat selection among landscapes within the Prairie Pothole Region (PPR). The influences of breeding population density and landscape composition were examined at all scales. At nest and patch scales, pintail nest survival varied with nest initiation date, nest habitat, pair density, and landscape composition. Nest habitat preference reflected patterns in nest survival suggesting nest habitat preference is adaptive. Preference was generally low for habitats with low nest survival (e.g., spring-seeded cropland) and high for habitats with high nest survival (e.g., idle grassland). Differences in preference among habitats weakened at high breeding density and in landscapes with more grassland. Population-level recruitment tended to be greater when pintails settled in landscapes that were wetter than normal, contained more grassland, and were moderately variable in local elevation. Pintails were strongly associated with wetter than normal landscapes but shifted into cropland-dominated landscapes and flatter landscapes when populations were high. My results indicated that pintails express adaptive habitat associations with density-dependence acting through buffer mechanisms. Finally, I use the results of the above analyses to, 1) model and map the estimated long-term average spatial abundance of pintail pairs across the PPR as a function of landscape-level covariates, and 2) construct a deterministic model predicting pintail productivity given habitat and landscape attributes. These models allow conservation efforts to be targeted to affect the most birds, and they allow estimation of the demographic response to conservation actions.

Once abundant across the Great Plains of North America, prairie-parkland elk (Cervus canadensis manitobensis) underwent a catastrophic population collapse and dramatic contraction of their overall range through the late 1800’s and the early 1900’s due to habitat loss (primarily from agricultural expansion) and unregulated hunting. Populations were able to recover in some areas following new hunting regulations and the establishment of protected areas. Prior to this study, the current distribution of prairie parkland elk was poorly understood, though it was established that they were largely relegated to large protected areas and made use of adjacent agriculture dominated landscapes. In order to effectively manage prairie-parkland elk so populations remain resilient to ongoing habitat loss, population reduction and disease risks, detailed mapping of their range and an understanding of the environmental factors most important to elk is essential. The purpose of my thesis is to characterize elk distribution and resource selection patterns in the prairie-parkland of Saskatchewan and Manitoba, Canada, at a landscape scale and assess the implications of distribution for species persistence, by using both local ecological knowledge (LEK) and biological research techniques in tandem. Integrating LEK with more conventional biological research can provide complementary data at contrasting time and spatial scales and facilitates comparison of multiple independent datasets. Furthermore, LEK research creates important opportunities to engage stakeholders in contributing knowledge and may facilitate relationships and contribute toward more effective resource management. I used three sets of biotelemetry-collar data from across Saskatchewan and Manitoba (n = 328 collared elk; 1998–2012), in conjunction with LEK from hunters, biologists and enforcement officers (n = 71 participants) to create a series of resource selection functions (RSFs) characterizing elk distribution across Saskatchewan and Manitoba. I gathered LEK in workshops where participatory mapping was conducted with local experts across the study area. The RSF analysis determined that prairie-parkland elk selected locations close to protected areas and far from high road density. Elk also selected areas with moderate amounts of mixed-wood and deciduous forests and herbaceous vegetation. Models developed with LEK only, biotelemetry collar data only and a combined dataset were all validated against an independent dataset of elk crop damage locations. All models predicted elk presence well. The RSF scores of the LEK only and radio-collar only models were not significantly different. Successful conservation management requires identifying which areas are most important to a species, and assessing if these areas are vulnerable to threats, as well as balancing human resource needs. Using the RSF-based maps of prairie-parkland elk distribution, I identified locations of high quality habitat (top 10% of RSF values) and determined which of those areas were vulnerable to agricultural expansion, forestry, disease, and hunting. I identified 81 high quality habitat areas with a combined total area of 30 753 km2. One or more vulnerability factor impacted 87% of the identified core area. High quality areas were clearly clustered around the boreal-prairie transition zone and large protected areas. The majority (88%) of high quality core areas were located within protected areas. A connectivity analysis using least cost path analysis determined that core habitat areas endemic with chronic wasting disease (CWD) in wild elk are highly connected to other high quality habitat areas. CWD thus has the potential to reduce cervid populations within the study area. My thesis results highlight that prairie-parkland elk populations in Saskatchewan and Manitoba remain threatened by habitat loss and disease, and emphasize the need for habitat conservation to prevent further population reduction. While elk populations have regained a small fraction of the range lost at the turn of the last century, they have not been able to re-establish with much success in the prairie portion of their range. I also determined that LEK can be as effective as conventional biological research approaches to develop RSFs. I also confirmed that stakeholders within the study are knowledgeable about elk behaviour. The distribution maps and identified areas of priority concern created in this thesis can provide important insights to support the management and maintenance of abundant elk populations.

An understanding of the adaptability of belugas (Delphinapterus leucas) to changing ice-conditions is required to interpret and predict possible changes in habitat selection in response to projected loss of sea ice throughout the circumpolar Arctic. Beluga spring distribution in the eastern Beaufort Sea was described by analyzing observations from aerial surveys conducted from 1975 to 1979. Repeated surveys along the Franklin Bay fast-ice edge in June 2008 were used to study the distribution and behaviour of belugas and bowheads. Despite inter-annual variability in ice extent, belugas consistently selected areas with water depths of 200-500 m, heavy ice concentrations (8/10 to 10/10) and seafloor slope ≥0.5 degrees in spring 1975 to 1979. While predator avoidance may partially explain the observed distribution, foraging success likely has more influence on beluga habitat selection in the spring. In ice-covered offshore regions, belugas may be engaged in under-ice and deep water foraging on Arctic cod (Boreogadus saida). In lighter ice years, belugas may expand their distribution and shift shoreward to take advantage of high prey densities along fast-ice edges. Both belugas and bowheads appeared to be feeding along the Franklin Bay ice edge in June 2008. More research is required to examine and compare possible changes in distribution since the late 1970s and to investigate the factors driving the patterns described.