Graduate Theses & Dissertations


Interpretation of forest harvest recovery using field-based and spectral metrics in a Landsat time series in Northwestern Ontario
The forestry sector has a well-developed history of using remote sensing to identify structural characteristics of forests and to detect and attribute changes that occur in forested landscapes. Monitoring the recovery of disturbed forests is an important factor in long term forest management. However, forest that is recovered spectrally may not be recovered when considered in terms of a Free to Grow assessment. A Free to Grow assessment is used in Ontario to determine whether a disturbed site will likely achieve a desired future state, i.e., is recovered according to a forestry perspective. The objective of this research was to determine the relationship between a pixel-based Landsat Time Series of spectral recovery and the results of Free to Grow assessments. Spectral trajectories were generated from representative pixels within known harvested forest areas. Results indicate that while Free to Grow sites often achieve spectral recovery (>90%), many non-Free to Grow sites were classified as spectrally recovered, suggesting that improved methods of spectral recovery monitoring are needed. Author Keywords: forest recovery, Free to Grow, Landsat Time Series, LandTrendr, Pixel-based, spectral recovery
White-Tailed Fear
The primary method used to maintain white-tailed deer (Odocoileus virginianus) populations at densities that are ecologically, economically, socially, and culturally sustainable is hunter harvest. This method considers only the removal of animals from the population (the direct effect) and does not conventionally consider the costs imposed on deer as they adopt hunter avoidance strategies (the risk effect). The impact of risk effects on prey can exceed that of direct effects and there is interest in applying this concept to wildlife management. Deer are potential candidates as they have demonstrated behavioural responses to hunters. I explored the potential of such a management practice by quantifying how human decisions around hunting create a landscape of fear for deer and how deer alter their space use and behaviour in response. I used a social survey to explore the attitudes of rural landowners in southern and eastern Ontario towards deer and deer hunting to understand why landowners limited hunting on their property. I used GPS tracking devices to quantify habitat selection by hunters and hunting dogs (Canis familiaris) to better understand the distribution of hunting effort across the landscape. I used GPS collars to quantify the habitat selection of deer as they responded to this hunting pressure. I used trail cameras to quantify a fine-scale behavioural response, vigilance, by deer in areas with and without hunting. Human actions created a highly heterogeneous landscape of fear for deer. Landowner decisions excluded hunters from over half of the rural and exurban landscape in southern and eastern Ontario, a pattern predicted by landowner hunting participation and not landcover composition. Hunter decisions on whether to hunt with or without dogs resulted in dramatically different distributions of hunting effort across the landscape. Deer showed a high degree of behavioural plasticity and, rather than adopting uniform hunter avoidance strategies, tailored their response to the local conditions. The incorporation of risk effects into white-tailed deer management is feasible and could be done by capitalizing on a better understanding of deer behaviour to improve current management practices or by designing targeted hunting practices to elicit a landscape of fear with specific management objectives. Author Keywords: Brownian bridge movement models, hunting, landscape of fear, resource utilization functions, risk effects, white-tailed deer
Discriminating grey wolf (Canis lupus) predation events in a multi-prey system in central Saskatchewan
I investigated if spatio-temporal behaviour of grey wolves (Canis lupus) determined via GPS collar locations could be used to discriminate predation events generally, and among prey species, in Prince Albert National Park during winter, 2013-2017. I used characteristics of spatio-temporal GPS clusters to develop a predictive mixed-effect logistic regression model of which spatial clusters of locations were wolf kill sites. The model suffered a 60 % omission error when tested with reserved data due to the prevalence of deer kills with correspondingly low handling time. Next, I found a multivariate difference in the percentage of habitat classes used by wolves in the 2 hours preceding predation events of different prey species, suggesting that wolf habitat use reflects prey selection at a fine-scale. My results highlight the difficulty and future potential for remoting discriminating wolf predation events via GPS collar locations in multi-prey ecosystems. Author Keywords: Canis lupus, GPS clusters, GPS collars, grey wolf, habitat use, predation
Syrphidae (Diptera) of northern Ontario and Akimiski Island, Nunavut
Syrphids, also known as hover flies (Diptera: Syrphidae) are a diverse and widespread family of flies. Here, I report on their distributions from a previously understudied region, the far north of Ontario, as well as Akimiski Island, Nunavut. I used samples collected through a variety of projects to update known range and provincial records for over a hundred species, bringing into clearer focus the distribution of syrphids throughout this region. I also analysed a previously un-tested trap type for collecting syrphids (Nzi trap), and report on results of DNA analysis for a handful of individuals, which yielded a potential new species. Author Keywords: Diptera, Ontario, range extension, Syrphidae
Habitat selection by sympatric Canada lynx (Lynx canadensis) and bobcat (Lynx rufus)
Range expansion by the bobcat (Lynx rufus) may be contributing to range contraction by the Canada lynx (Lynx canadensis), but interactions between them are not well understood. To investigate the potential for competition, I conducted a literature review of hierarchical habitat selection by these two species. I determined that the lynx and the bobcat select different resources at the first and second orders, and that the fourth order is under-studied compared to higher orders. I therefore conducted a snow-tracking study of fine-scale habitat selection by lynx and bobcat in an area of sympatry in northern Ontario. I found that the two species selected similar resources at the fourth order, but appeared to be allopatric at the level of the home range. These results suggest that competition is unlikely to occur between lynx and bobcat, and other factors should be considered as more probable causes of the lynx range contraction. Author Keywords: Bobcat, Canada lynx, Competition, Habitat selection, Scale, Snow tracking
cascading effects of risk in the wild
Predation risk can elicit a range of responses in prey, but to date little is known about breadth of potential responses that may arise under realistic field conditions and how such responses are linked, leaving a fragmented picture of risk-related consequences on individuals. We increased predation risk in free-ranging snowshoe hares (Lepus americanus) during two consecutive summers by simulating natural chases using a model predator (i.e., domestic dog), and monitored hare stress physiology, energy expenditure, behaviour, condition, and habitat use. We show that higher levels of risk elicited marked changes in physiological stress metrics including sustained high levels of free plasma cortisol which had cascading effects on glucose, and immunology, but not condition. Risk-augmented hares also had lowered daily energy expenditure, spent more time foraging, and decreased rest, vigilance, and travel. It is possible that these alterations allowed risk-exposed hares to increase their condition at the same rate as controls. Additionally, risk-augmented hares selected, had high fidelity to, and were more mobile in structurally dense habitat (i.e., shrubs) which provided them additional cover from predators. They also used more open habitat (i.e., conifer) differently based on locale within the home range, using familiar conifer areas within cores for rest while moving through unfamiliar conifer areas in the periphery. Overall, these findings show that prey can have a multi-faceted, highly plastic response in the face of risk and can mitigate the effects of their stress physiology given the right environmental conditions. Author Keywords: behaviour, condition, daily energy expenditure, predator-prey interactions, snowshoe hare, stress physiology
Effects of Geographic Factors on the Wild Harvest of Large Mammals across North America
While the harvest of mammals is monitored in each jurisdiction across Canada and the USA, there has been no analysis of this wild harvest at a continental scale across North America. The recreational wild harvest of large mammals varies geographically across North America, and I hypothesized that this variation is influenced by both anthropogenic and other environmental factors on the landscape. I tested this hypothesis using annual harvest tallies collected by Conservation Visions Inc. for mammals for each state, provincial, and territorial jurisdiction in Canada and the USA. I built multiple additive models of the harvest, in one harvest year, 2015 – 2016, to test for landscape gradients that explain the variation in harvest levels for seven large mammal species: white-tailed deer (Odocoileus virginianus), black bear (Ursus americanus), bighorn sheep (Ovis canadensis), elk (Cervus canadensis), mule deer (Odocoileus hemionus), pronghorn (Antilocapra americana), and moose (Alces alces). I built these models from a suite of nine putative predictor variables that comprised landcover, human footprint, and evapotranspiration. For all large mammal species except for pronghorn, anthropogenic influence had a positive effect on the wild harvest density, consistent with the idea that the proximity of human populations and roads are important for fostering wild harvest activity by providing hunters access to hunting areas. The harvest of white-tailed deer, elk, and pronghorn were negatively affected by vegetation structure, urbanization, and primary productivity, respectively. Understanding the recreational wild harvest at a broad-spatial scale provides a unique perspective of the North American model of wildlife conservation and spurs future comparative analyses of the wild harvest across spatial scales. Author Keywords: Anthropogenic Influence, Hunting, Large Mammals, Primary Productivity, Vegetation Structure, Wild Harvest
spatial and temporal distribution of tabanid (Chrysops, Hybomitra and Tabanus) species in the Nakina district of northwestern Ontario
This thesis focused on expanding knowledge of Hybomitra, Chrysops and Tabanus (Diptera: Tabanidae) distributions north of Lake Nipigon, Ontario, in a managed boreal forest. As land use and climate changes accelerate, there is increased pressure to increase knowledge from which to monitor changes. In 2011 and 2012, 8928 individuals representing, 44 species were captured using sweep netting. Major northward range extensions were observed for Chrysops shermani, C. aberrans and Tabanus fairchildi. Smaller range extensions and in-fills were observed for another 15 species. 23 species had exntensions to their previously known seasonal range. C. carbonarius was the only species that showed an extension to both sides of its season. In general, harvested stands had 50% more individuals and 30% greater species richness than younger stands. A possible link between stand age and interspecific competition was identified. Information has been provided to build baseline of species richness, relative abundance and distribution of Tabanid flies. Author Keywords: diptera, distribution, natural history, northern Ontario, species range, tabanid
influence of landscape features on the harvest of caribou (Rangifer tarandus) on the island of Newfoundland
Hunting represents the principal tool for managing populations of migratory caribou (Rangifer tarandus), but harvest may be affected by landscape features that govern animal distribution and hunter access. Such effects are unclear. I capitalized on an existing dataset of 21 355 caribou harvest records, 1980 – 2009, to determine the influence of landscape features on caribou harvest across the island of Newfoundland. Using a landcover map and spatial data for anthropogenic features, I modelled caribou harvest at the island scale for three phases of numerical change (growth in the 1980s, cessation of growth in the 1990s, decline in the 2000s) and harvest type (total harvest, resident harvest of males and females, resident harvest of males, resident harvest of females, and non-resident harvest of males) in relation to multiple putative predictor variables: proportion of lichen cover and distances to nearest forest cut, road, outfitter, transmission line, and town. I did the same analysis for seven individual Caribou Management Areas (CMAs). At the island scale, the number of harvested caribou increased with proximity to the nearest forest cut and with greater proportions of lichen habitat. I attribute this to landscape features that provide forage for caribou, but also access and caribou visibility for hunters. Caribou harvest increased in proximity to transmission lines for the harvest of caribou by resident hunters in the 2000s, which could be a result of more risk-prone foraging Newfoundland caribou. Non-resident hunters harvested greater numbers of male caribou further from towns, likely a result of the placement of outfitter camps and activities. At the management area scale, in most instances, more caribou harvest occurred in close proximity to transmission lines. Proximity to forest cuts and high proportions of lichen were still important landscape features leading to a greater harvest. I conclude that the caribou harvest was largely governed by hunter access and visibility of their prey, augmented by open habitats preferred by caribou. KEYWORDS Caribou, Newfoundland, Rangifer tarandus, harvest, hunting, management area, landscape, human disturbances, game species vulnerability. Author Keywords: caribou, game species vulnerability, harvest, hunting, newfoundland, rangifer tarandus
Impact of Agricultural Land Use on Bobolink Occurrence, Abundance, and Reproductive Success in an Alvar Landscape
Pastures and hayfields provide surrogate habitat for many declining grassland birds. Understanding agricultural land use dynamics and habitat quality can impact conservation of grassland species. I investigated 1) patterns of land use change in protected and unprotected sites in relationship to Bobolink occurrence in Carden, Ontario, Canada and 2) whether continuous grazing at lowmoderate cattle densities provided suitable breeding habitat, using both real and artificial nests. I replicated the 2001-2005 Ontario Breeding Bird Atlas to evaluate site habitat changes and Bobolink population trends. In continuously grazed pastures and late-cut hayfields, I monitored Bobolink abundance and reproductive success and modeled daily survival rate of nests using habitat management, vegetation structure, and prey availability. Results indicated that Bobolink have declined by -15.3% since 2001 in Carden; losses were explained almost entirely by changes from suitable breeding habitat (e.g. hayfields) to tilled land or by the colonization of shrubs. For pastures, stocking densities of ≤ 1Animal Units/ha did not negatively impact Bobolink. Year and caterpillar biomass, and vegetation height were the strongest predictors of nesting success in pastures and hayfields, respectively. Focus on the preservation of suitable habitat on the breeding grounds and management on small-scale beef farms can contribute to conservation action for this declining species. Author Keywords: agricultural management, avian ecology, Bobolink, continuous grazing, grassland birds, nest success
Island Syndrome and Stress Physiology of Mice in the Genus Peromyscus
Biological differences between island and mainland conspecifics have been well studied, but few studies have addressed differences in stress physiology. Stressors, such as predation and competition for resources, cause the release of glucocorticoids (GCs). Characteristics of island wildlife, called “island syndrome”, are attributed to low levels of predators and competitors. I tested the hypothesis that island syndrome includes differences in GC levels between island and mainland rodents using two approaches; first, using white-footed mice (Peromyscus leucopus) from a near-shore archipelago (Thousand Islands, Ontario) and the nearby mainland; second, using study-skins of deer mice (Peromyscus maniculatus) from two archipelagos offshore of Vancouver Island, British Columbia. White-footed mice in the near-shore archipelago did not show characteristics of island syndrome, or changes in GC levels (feces and hair); however deer mice from both archipelagos in British Columbia were heavier and had lower hair GCs for their size than Vancouver Island mice. Author Keywords: Glucocorticoids, Island rule, Island syndrome, Peromyscus, Stress physiology
Reproductive Fitness of Smallmouth Bass (Micropterus dolomieu) Under Heterogeneous Environmental Conditions
Identifying the biotic and abiotic factors that influence individual reproductive fitness under natural conditions is essential for understanding important aspects of a species’ evolutionary biology and ecology, population dynamics, and life-history evolution. Using next generation sequencing technology, I developed five microsatellite multiplex reactions suitable for conducting large scale parentage analysis of smallmouth bass, Micropterus dolomieu, and used molecular pedigree reconstruction techniques to characterize the genetic mating system and mate selection in adult smallmouth bass nesting in Lake Opeongo, Ontario, Canada. I used multivariate spatial autocorrelation analysis to indirectly infer the occurrence and extent of natal philopatry among spawning adults, to assess the strength and direction of sex-bias in natal dispersal patterns, and to evaluate the degree of nest site fidelity and breeding dispersal of spawning adults. I also evaluated how differences in littoral zone water temperature caused by wind-induced seiche events influence the relative reproductive success of spawning adults. Lastly, I provide a synopsis of potential future research aimed at further exploring factors that influence the reproductive fitness of smallmouth bass in Lake Opeongo. This information will contribute to our understanding of the factors regulating smallmouth bass populations, and provide insight into the factors controlling the variance in individual reproductive success and thus recruitment dynamics in this species. Author Keywords: Dispersal, Fitness, Mate selection, Mating systems, Philopatry


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