Schaefer, James

The ecology and evolution of animal migration – an integrative approach to the drivers of phenotypic variation

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Creator (cre): Bonar, Maegwin, Thesis advisor (ths): Northrup, Joseph M, Thesis advisor (ths): Shafer, Aaron BA, Degree committee member (dgc): Koen, Erin, Degree committee member (dgc): Schaefer, James, Degree granting institution (dgg): Trent University
Abstract:

Animal migrations are ubiquitous and one of the most threatened ecological processes globally. Because of the multifaceted nature of migration – seasonal movements between home ranges – it can be difficult to tease apart the underlying mechanisms influencing this behaviour. It is necessary to understand these mechanisms, not only to deepen our fundamental understanding of migration in animals, but also because migrations in many species are vulnerable to environmental change. In Chapter 2, I first systematically identify the broad proximate drivers of migration and offer generalities across vertebrate taxa. I quantitatively reviewed 45 studies and extracted 132 observations of effect sizes for internal and external proximate drivers that influenced migration propensity. Through this meta-analysis, I found that internal and external drivers had a medium and large effect, respectively, on migration propensity. Predator abundance and predation risk had a large effect on migration propensity, as did individual behaviour. Of the studies that examined genetic divergence between migrant and resident populations, 64% found some genetic divergence between groups. In Chapter 3, I explore the genetic basis for migration and identified genes associated with migration direction from pooled genome-wide scans on a population of 233 migrating female mule deer (Odocoileus hemionus) where I identified genomic regions including FITM1, a gene linked to the formation of lipids, and DPPA3, a gene linked to epigenetic modifications of the maternal line. These results are consistent with the underlying genetic basis for a migratory trait which contributes to the additive genetic variance influencing migratory behaviours and can affect the adaptive potential of a species. Finally, in Chapter 4 I used a pedigree-free quantitative genetic approach to estimate heritability and sources of environmental variation in migration distance, timing, and movement rate of the same population of mule deer. I found low heritability for broad patterns of migration timing, and greater variation in heritability for behaviours during migration, with low heritability for distance and duration and high heritability for movement rate along the route. Insights into the genetic and environmental sources of variation for migration are critical both for the eco-evolutionary dynamics of migration behaviour, and for the conservation of species whose migrations may be vulnerable to environmental change. My thesis reveals that broad patterns of migration are driven largely by environmental effects while within these broad patterns, migration behaviour is driven to a measurable degree by genetic variation.

Author Keywords: heritability, migration, Odocoileus hemionus, reduced representation sequencing, whole genome sequencing

2024

Behavioural ecology and population dynamics of freshwater turtles in a semi-urban landscape at their northern range limit

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Creator (cre): Auge, Anne-Christine, Thesis advisor (ths): Murray, Dennis, Thesis advisor (ths): Blouin-Demers, Gabriel, Degree committee member (dgc): Schaefer, James, Degree granting institution (dgg): Trent University
Abstract:

Species are faced with a variety of challenges in the environment, including natural challenges, such as variability in ambient temperature, and anthropogenic threats, such as habitat transformation associated with urbanisation. Understanding how animals respond to these kinds of challenges can advance the field of behavioural ecology and guide management decisions for wild species. Yet, we still have limited understanding of the extent of natural and human-caused impacts on animal behaviour and population dynamics, and lack robust assessment of behaviour in free-ranging animals. Using novel miniaturised biologging technologies, I characterised and validated behaviour in two freshwater turtle species: Blanding's turtles (Emydoidea blandingii) and Painted turtles (Chrysemys picta). Further, I investigated how these two ectothermic species navigate a thermally heterogeneous landscape near their northern range limit, by comparing selected and available ambient temperatures. I showed that turtles preferred locations that were, on average, warmer and less variable in temperature than the available environment, and that this thermal sensitivity was greatest early in the year, and at fine spatial scales that likely matched the species' perception of the environment. Lastly, I assessed whether urban development was compatible with long-term viability of a Blanding's turtle population, by monitoring habitat change and turtle survival over one decade of ongoing residential and road development. I found that Blanding's turtle habitat quantity and connectivity declined in the area, which coincided with high road mortality and severe declines in turtle survival and population size, especially in adult females. I concluded that urban development and current road mortality rates are incompatible with the long-term viability of this at-risk turtle population. Overall, my findings demonstrate the importance of variation in the thermal environment and anthropogenic impacts on habitat in shaping the behaviour and population dynamics of this species-at-risk.

Author Keywords: animal behaviour, biologging, ectotherms, habitat selection, temperature, urbanisation

2022

Managing Through Change: Indigenous knowledge, climate change and the case of moose in Nunatsiavut

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Creator (cre): Rosa, Katie, Thesis advisor (ths): Furgal, Chris, Degree committee member (dgc): Schaefer, James, Degree committee member (dgc): Snook, Jamie, Degree granting institution (dgg): Trent University
Abstract:

Arctic ecosystems are increasingly altered by climate change, and some wildlife species, like moose, are adapting to these new conditions. Indigenous knowledge and values, such as those held by Inuit, can provide insight into adaptive wildlife management and may improve ecosystem resiliency. This thesis seeks to address the following question: What is the potential role of Indigenous knowledge in managing wildlife under climate change? This thesis follows a qualitative exploratory design involving 1) a systematic literature review of the peer-reviewed literature and 2) a case study on moose in Nunatsiavut in which 35 interviews and participatory mapping were conducted with Inuit beneficiaries. The results demonstrate a range of potential roles for Indigenous knowledge and values in managing species impacted by climate change. The case study of moose in Nunatsiavut has applicability across the Canadian Arctic where the sustainability of harvested species is at risk.

Author Keywords: Arctic, climate change, Indigenous knowledge, moose, Nunatsiavut, wildlife management

2021

The Diversity, Biogeography, and Functional Traits of Native Bees from Ontario's Far North and Akimiski Island, Nunavut

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Creator (cre): Vizza, Kayla Marie, Thesis advisor (ths): Beresford, David V, Degree committee member (dgc): Schaefer, James, Degree granting institution (dgg): Trent University
Abstract:

Bees (clade Anthophila), are poorly studied in northern Canada, as these regions can be difficult to access and have a short growing season. This study examined bees from two such regions: Ontario's Far North, and Akimiski Island, Nunavut. I present this study as the largest biogeographical study of bees performed in these remote areas to enhance knowledge of northern native bees. I found 10 geographically unexpected species in Ontario and on Akimiski Island. Rarefaction and the Chao 1 Diversity Index showed that Akimiski is nearly as diverse as the Far North of Ontario, a significantly larger area. I also found, based on log femur length versus latitude, Bombus worker size was consistent with Bergmann's rule, and there were no apparent statistical differences in the community weighted means of functional traits between the Far North's Boreal Shield and Hudson Bay Lowlands ecozones. This work provides invaluable knowledge of the native bee species from these regions, which has implications for their future conservation.

Author Keywords: Akimiski Island, Bergmann's rule, Chao 1, Community-weighted means, native bees, rarefaction

2019

Assessing and Mitigation the Impacts of Mining-induced Flooding on Arctic-nesting Birds

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Creator (cre): Holmes, Gillian Irene, Thesis advisor (ths): Nol, Erica, Thesis advisor (ths): Smith, Paul A, Degree committee member (dgc): Schaefer, James, Degree granting institution (dgg): Trent University
Abstract:

Mining and resource development are growing industries in the Arctic, resulting in increased conflict with wildlife. Best practices for mitigation require an understanding of the potential ecological effects. One such effect concerns the flooding of terrestrial bird habitat from dewatering of lakes during mining pit development. I first assessed the efficacy of bird deterrents to mitigate impacts of mining-induced flooding on arctic-nesting birds at a gold mine in Nunavut. I used a Before-After Control Impact (BACI) design to determine changes in male territory densities, between year and treatment types (Control, High and Low Deterrent Intensity). Additionally, I assessed whether deterrents impacted daily survival rates of two passerine species, and the incubation behaviour of female Lapland Longspur. Finally, I quantified nest losses during the breeding season due to direct flooding of the tundra nesting habitat caused by mining operations. Deterrents did not affect male territory densities and neither deterrent treatment nor year affected the daily survival rate of nesting passerines. Female Lapland Longspurs exposed to deterrents exhibited more incubation off-bouts than control females. I documented six flooded nests. Deterrents used in this study appear to be ineffective in mitigating nesting in potential zones of impact. Incidental take accounted for about 1.2% of all nests found in the 0.48 km2 Whale Tail Lake study area.

Author Keywords: arctic-nesting birds, audio deterrents, incidental take, mining and resource development, nest incubation, visual deterrents

2022

ECTOPARASITIC INFLUENCES OF DIPTERA ON THE ACTIVITY AND BEHAVIOUR OF WOODLAND CARIBOU (RANGIFER TARANDUS) IN A MANAGED BOREAL FOREST LANDSCAPE IN NORTHERN ONTARIO

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Creator (cre): Raponi, Marco, Thesis advisor (ths): Beresford, David, Thesis advisor (ths): Schaefer, James, Degree committee member (dgc): Patterson, Brent, Degree granting institution (dgg): Trent University
Abstract:

Caribou experience direct and indirect negative effects of harassment from biting flies, influencing behavior and activity on several spatial and temporal scales. I used systematic insect collection surveys during the summers of 2011 and 2012 to examine the spatial and temporal distributions of black flies (Simuliidae), mosquitoes (Culicidae), and deer flies and horse flies (Tabanidae) in a managed boreal forest in northern Ontario. Mosquitoes had a positive association with densely treed habitats, whereas black flies more often occurred in open areas, and tabanids had a strong presence in all habitat types. Habitats in proximity to large bodies of water had fewer biting flies than inland areas. Young stands supported higher abundances of tabanids despite vegetation community type. Next, I tested for seasonal effects of biting fly abundance on caribou activity by modelling the seasonal trend in abundance for each fly family for each year and compared this to an index of daily activity for 20 radio-collared female caribou in 2011 and 10 females in 2012. I modeled this index of caribou activity for each animal in each year and extracted the set of partial correlation coefficients from multiple regressions to test for effects of biting fly abundances on caribou activity. Caribou reduced their daily activity when tabanids were more numerous, and increased activity when mosquitoes were numerous. This divergent response may reflect a difference in the efficacy of moving to reduce harassment, owing to the stronger flight capabilities of tabanids.

Author Keywords: Activity, Anthropogenic Disturbance, Behaviour, Insect harassment, Temporal distribution, Woodland Caribou

2014

Moving North: Habitat Selection and Survival of the Wild Turkey at its Northern Range Edge

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Creator (cre): Niedzielski, Britney Jean, Thesis advisor (ths): Bowman, Jeff, Degree committee member (dgc): Patterson, Brent, Degree committee member (dgc): Schaefer, James, Degree granting institution (dgg): Trent University
Abstract:

Since their successful reintroduction, the eastern wild turkey (Meleagris gallopavo silvestris) has expanded its range north. Due to different and potentially more severe limiting factors, management approaches generalized from studies within the historical range may not be appropriate to apply to northern populations. To better understand northern wild turkey ecology, GPS and VHF transmitters were used to track habitat selection and survival of female turkeys at the species northern range edge in Ontario, Canada. These northern turkeys exhibited larger seasonal home range sizes relative to those in their historical range, and selected deciduous forest and pasture and fields within the study area. Supplemental food was also selected by turkeys when choosing autumn and winter ranges. The northern turkeys also suffered a low annual survival rate, and high mortality from predation. These findings underscore the challenges of maintaining turkey populations in northern environments, and will help inform management strategies.

Author Keywords: Eastern Wild Turkey, Euclidean distance analysis, Habitat selection, Meleagris gallopavo silvestris, Northern range edge, Survival

2014

Calving site selection and fidelity in a restored elk (Cervus elaphus) herd in Bancroft, Ontario, Canada

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Names:
Creator (cre): Allan, Michael Ross, Nicholas, Thesis advisor (ths): Davies, Chris, Thesis advisor (ths): Schaefer, James, Degree committee member (dgc): Rosatte, Richard C, Degree granting institution (dgg): Trent University
Abstract:

ABSTRACT

Calving site selection and fidelity in a restored elk (Cervus elaphus) herd in Bancroft

Ontario, Canada.

Michael R. Allan

Parturition site selection by ungulates is believed to be influenced by forage abundance and concealment from predators. In 2011 and 2012, I used vaginal implant transmitters and movements to identify calving sites for 23 GPS collared elk (Cervus elaphus) from a restored herd. I tested the hypothesis that maternal elk used sites with higher forage and denser concealment compared to pre-calving sites at micro and macrohabitat levels. I detected no significant microhabitat differences from direct measurements of vegetation. At the macrohabitat scale, based on proximity of landcover classes, mean distances to hardwood forests was significantly less for calving (153 m) than pre-calving sites (198 m).

Site fidelity is hypothesized to offer security in terms of familiarity to an area. I tested the hypothesis that females demonstrated fidelity to their previous year's location during pre-partum, parturition, post partum, breeding and winter periods. Elk were more philopatric during parturition and post partum than during breeding. Compared to winter elk were more philopatric during pre-partum, parturition and post-partum periods. Expressed as distance between consecutive-year calving locations, site fidelity varied with 27% of females exhibiting high (<1 km), 18% moderate and 55% (>2.9 km) low fidelity.

I measured nearest-neighbour distances at calving time, exploring the hypothesis that females distance themselves from conspecifics. Elk increased the average distances

to collared conspecifics during parturition; however, sample sizes were small. This strategy might influence calving site selection.

Rapid movement prior to parturition, low site fidelity and spacing-out of females during parturition appear to be strategies to minimize predator risk and detection. Little evidence of selection for vegetation structure suggests this may not be limiting to these elk.

Author Keywords: calving, elk, fidelity, movement, parturition, selection

2014

Hybridization Dynamics between Wolves and Coyotes in Central Ontario

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Creator (cre): Benson, John, Thesis advisor (ths): Patterson, Brent R, Degree committee member (dgc): Wilson, Chris, Degree committee member (dgc): Schaefer, James, Degree granting institution (dgg): Trent University
Abstract:

Eastern wolves (Canis lycaon) have hybridized extensively with coyotes (C. latrans) and gray wolves (C. lupus) and are listed as a `species of special concern' in Canada. Previous studies have not linked genetic analysis with field data to investigate the mechanisms underlying Canis hybridization. Accordingly, I studied genetics, morphology, mortality, and behavior of wolves, coyotes, and hybrids in and adjacent to Algonquin Provincial Park (APP), Ontario. I documented 3 genetically distinct Canis types within the APP region that also differed morphologically, corresponding to putative gray wolves, eastern wolves, and coyotes. I also documented a substantial number of hybrids (36%) that exhibited intermediate morphology relative to parental types. I found that individuals with greater wolf ancestry occupied areas of higher moose density and fewer roads. Next, I studied intrinsic and extrinsic factors influencing survival and cause-specific mortality of canids in the hybrid zone. I found that survival was poor and harvest mortality was high for eastern wolves in areas adjacent to APP compared with other sympatric Canis types outside of APP and eastern wolves within APP. Contrary to previous studies of wolves and coyotes elsewhere, I hypothesized that all Canis types exhibit a high degree of spatial segregation in the Ontario hybrid zone. My hypothesis was supported as home range overlap and shared space use between neighboring Canis packs of all ancestry classes were low. Territoriality among Canis may increase the likelihood of eastern wolves joining coyote and hybrid packs and exacerbate hybridization. Canids outside APP modified their use of roads between night and day strongly at high road densities (selecting roads more at night), whereas they responded weakly at lower road densities (generally no selection). Individuals that survived exhibited a highly significant relationship between the difference in their night and day selection of roads and availability of roads, whereas those that died showed a weaker, non-significant response. My results suggest that canids in the unprotected landscape outside APP must balance trade-offs between exploiting benefits associated with secondary roads while mitigating risk of human-caused mortality. Overall, my results suggest that the distinct eastern wolf population of APP is unlikely to expand numerically and/or geographically under current environmental conditions and management regulations. If expansion of the APP eastern wolf population (numerically and in terms of its geographic distribution) is a conservation priority for Canada and Ontario, additional harvest protection in areas outside of APP may be required. If additional harvest protection is enacted, a detailed study within the new areas of protection would be important to document specific effects on eastern wolf population growth.

Author Keywords: Canis, coyotes, eastern wolves, hybridization, resource selection, survival

2013

The cascading effects of risk in the wild: how snowshoe hares (Lepus americanus) respond to the threat of predation

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Creator (cre): Boudreau, Melanie R., Thesis advisor (ths): Murray, Dennis L, Degree committee member (dgc): Schaefer, James, Degree committee member (dgc): Burness, Gary, Degree granting institution (dgg): Trent University
Abstract:

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

2019