Ecology

The influence of landscape features on the harvest of caribou (Rangifer tarandus) on the island of Newfoundland

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Names:
Creator (cre): McNamara, Jordan, Thesis advisor (ths): Schaefer, James, Degree committee member (dgc): Pond, Bruce, Degree committee member (dgc): Patterson, Brent, Degree granting institution (dgg): Trent University
Abstract:

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

2018

Enhancing post-mortem interval estimates: refinements of technical, morphometrical, and species considerations within forensic entomology

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Names:
Creator (cre): Bourne, Donald Richard, Thesis advisor (ths): Beresford, David V, Thesis advisor (ths): Kyle, Christopher J, Degree committee member (dgc): LeBlanc, Helene N, Degree granting institution (dgg): Trent University
Abstract:

The growth of immature insects that develop on human remains can be used to estimate a post-mortem interval (PMI). PMI estimate confidence is negatively affected by: larval killing and preservation methods altering their size, limited morphological parameters to assess larval growth and therefore age, and few available alternate species development data. I compared live specimens to preserved specimens of the same development stages to assess the effects of killing-preservation techniques on morphology, and I introduce a new method that uses digital photography to examine maggot mouthparts for stage grading of Phormia regina. Digital photographic methods enable live insects to be quantified and improve approximations of physiological age. I then use these digital methods to produce a growth-rate model for a beetle commonly found on human remains, Necrodes surinamensis, providing data for PMI estimates that was previously unavailable.

Author Keywords: Forensic Entomology, Insect development, Morphometrics, Necrodes surinamensis, Phormia regina, Postmortem interval

2018

Island Syndrome and Stress Physiology of Mice in the Genus Peromyscus

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Names:
Creator (cre): Stewart, Nathan, Thesis advisor (ths): Burness, Gary, Degree committee member (dgc): Bowman, Jeff, Degree committee member (dgc): Schaefer, James, Degree granting institution (dgg): Trent University
Abstract:

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

2017

Linking Inuit and Scientific Knowledge and Observations to Better Understand Arctic Char (Salvelinus alpinus (L.)) Community Monitoring

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Names:
Creator (cre): Knopp, Jennie A., Thesis advisor (ths): Furgal, Chris M, Degree committee member (dgc): Whillans, Tom, Degree committee member (dgc): Reist, James D, Degree granting institution (dgg): Trent University
Abstract:

Arctic Char (Salvelinus alpinus (L.)) have been, and remain, an important

subsistence resource for the Inuvialuit, the Inuit of the western Canadian Arctic. The effects

of climate variability and change (CVC) in this region have been noticeably increasing over

the past three decades. There are concerns as to how CVC will affect Arctic Char and the

Inuvialuit who rely on this resource as they will have to adapt to changes in the fishery.

Community-based monitoring, is an important tool for managing Arctic Char. Therefore,

my dissertation focused on the central question of: Which community-based monitoring

factors and parameters would provide the information needed by local resources

users and decision-makers to make informed choices for managing Arctic Char

populations in light of CVC?

This question is investigated through an exploratory research approach and a mixed

method research design, using both scientific and social science methods, and quantitative

(scientific ecological knowledge and observation) and qualitative (Inuvialuit knowledge

and observation) information. It is formatted as three journal manuscripts, an introduction,

and an integrative discussion. The first manuscript examines potential habitat parameters

for monitoring landlocked Arctic Char condition in three lakes on Banks Island in the

Inuvialuit Settlement Region. The second manuscript examines potential local

environmental parameters for monitoring landlocked Arctic Char growth in the same three

lakes. The third manuscript investigates aspects of Arctic Char community-based

monitoring programs (CBMP) in the Canadian North that have led to the sustained

collection of useful data for management of the resource.

This dissertation makes contributions to the field of research by demonstrating the

utility of a mixed methods approach. The results demonstrate similarities and differences

in char growth and condition within and among Capron, Kuptan and Middle lakes on Banks

Island. This supports both lake-specific and regional climate-driven changes, meaning both

lake habitat and local environmental monitoring parameters should be used in char CBMP.

The investigation of char CBMP across northern Canada demonstrates that an adaptive

monitoring approach is important for subsistence fisheries, as changing lifestyles and

environmental changes impacting a fishery can have direct effects on the successful

operation of char CBMP.

Author Keywords: Arctic Char, community-based monitoring, environment, Inuit Knowledge, mixed methods, Traditional Knowledge

2017

Socio-Ecology and the Sacred: A Comparative Study of Entanglement and Natural Sites in Tropical Asia

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Names:
Creator (cre): Mody, Zankhna, Thesis advisor (ths): Iannone, Gyles, Degree committee member (dgc): Conolly, James, Degree committee member (dgc): Lohmann, Roger, Degree granting institution (dgg): Trent University
Abstract:

Within the complex socio-ecological systems of South and Southeast Asia, ancient sacred natural sites were created by, and imbued with, cultural and ideological values. These landscapes are liminal spaces or threshold environments between cultivated areas and wilder spaces; the practice of creating and maintaining them persists from ancient to modern times. This thesis examines sacred natural sites in three early state formations from 800 – 1400 CE: the Khmer (Cambodia), the Sinhalese (Sri Lanka) and the Chola (South India), why they persisted over time, and what significance they held. Several ancient sacred natural sites are active parts of societies today, and the ones chosen for this study span several categories: mountains, rivers, forests/groves, and caves. Using the paradigm of entanglement theory in a comparative context, this thesis analyzes sacred natural sites acting as key socio-ecological nodes enmeshed in complex dependent relationships within the landscapes of the South and Southeast Asia.

Author Keywords: Comparative study, Entanglement theory, Sacred natural sites, Socio-ecological systems, South Asia, Tropical Societies

2018

The Effects of Geographic Factors on the Wild Harvest of Large Mammals across North America

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Names:
Creator (cre): Millward, Brian, Thesis advisor (ths): Schaefer, James, Degree committee member (dgc): Mahoney, Shane, Degree committee member (dgc): Franklin, Steven, Degree granting institution (dgg): Trent University
Abstract:

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

2019

Agriculture as Niche Construction: Eco-Cultural Niche Evolution During the Neolithic (c. 6200 - 4900 BC) of the Struma River Valley

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Names:
Creator (cre): Whitford, Brent Robbie, Thesis advisor (ths): Conolly, James, Degree committee member (dgc): Dubreuil, Laure, Degree committee member (dgc): Fitzsimons, Rodney, Degree granting institution (dgg): Trent University
Abstract:

The Neolithic Period (c. 6200 – 4900 BC) in the Struma River Valley led to numerous episodes of cultural diversification. When compared with the neighbouring regions, the ecological characteristics of the Struma River Valley are particularly heterogeneous and the Neolithic populations must have adapted to this distinctive and localized ecological setting. It then becomes reasonable to ask if the evolution of cultural variability in the Struma River Valley was at least partially driven by the ecological setting and differentiation in the evolution of the early agricultural niche. In this thesis, I apply an approach based on niche construction theory and Maxent species distribution modeling in order to characterize the relationship between culture and ecology during each stage of the Neolithic Period and to assess diachronic change. An interpretation of the results demonstrates that the continuous reconstruction of the early agricultural niche allowed for settlement expansion into new eco-cultural niches presenting different natural selection pressures and that cultural change followed. I also found that cultural and historical contingencies played an equally important role on the evolution of populations and that ecological factors alone cannot account for the numerous episodes of cultural diversification that occurred throughout the region.

Author Keywords: Agriculture, Bulgaria, Eco-cultural Niche Modeling, Greece, Neolithic, Niche Construction

2017

Assessment of an adult lake sturgeon translocation (Acipenser fulvescens) reintroduction effort in a fragmented river system

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Names:
Creator (cre): Boothroyd, Maggie, Thesis advisor (ths): Wilson, Chris C, Thesis advisor (ths): Whillans, Tom, Degree committee member (dgc): Haxton, Tim, Degree granting institution (dgg): Trent University
Abstract:

North American freshwater fishes are declining rapidly due to habitat fragmentation, degradation, and loss. In some cases, translocations can be used to reverse local extirpations by releasing species in suitable habitats that are no longer naturally accessible. Lake sturgeon (Acipenser fulvescens) experienced historical overharvest across their distribution, leading to endangered species listings and subsequent protection and recovery efforts. Despite harvest and habitat protections, many populations do not appear to be recovering, which has been attributed to habitat alteration and fragmentation by dams. In 2002, 51 adult lake sturgeon from the Mattagami River, Ontario, Canada were translocated 340 km upstream to a fragmented 35 km stretch of the river between two hydroelectric generating stations, where sturgeon were considered extirpated. This study assessed the translocation effort using telemetry (movement), demographics and genetic data. Within the first year, a portion of the radio-tagged translocated individuals dispersed out of the release area, and released radio-tagged individuals used different areas than individuals radio-tagged ten years later. Catches of juvenile lake sturgeon have increased over time, with 150 juveniles caught within the duration of this study. The reintroduced population had similar genetic diversity as the source population, with a marked reduction in effective population size (Ne). The results indicate that the reintroduction effort was successful, with evidence of successful spawning and the presence of juvenile lake sturgeon within the reintroduction site. Overall, the results suggest adult translocations may be a useful tool for re-establishing other extirpated lake sturgeon populations.

Author Keywords: conservation, endangered species, lake sturgeon, reintroduction, telemetry, translocation

2018

Using automated radio-telemetry to link food availability, reproductive success, and habitat use of Barn Swallows (Hirundo rustica erythrogaster)

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Names:
Creator (cre): Lenske, Ariel, Thesis advisor (ths): Nocera, Joseph J, Degree committee member (dgc): Schaefer, James A, Degree committee member (dgc): Nol, Erica, Degree granting institution (dgg): Trent University
Abstract:

Drivers of North American Barn Swallow population declines are not well understood, but foraging habitat loss is thought to be a contributing factor. Determining patterns of habitat use is challenging for swallows because they move rapidly but are too small to carry GPS tags. We showed that automated radio-telemetry could be used to track the movements of swallows with enough accuracy (median error 250 m) to monitor local habitat use. We then combined information on breeding Barn Swallows habitat use, land cover, aerial insect abundance, and fledging success to test for a link between foraging habitat quality and reproductive success. Foraging activity was concentrated within 600 m of nest sites and varied with land cover; however, responses to land cover were not consistent across birds. Aerial insects were most abundant near wetlands and least abundant near open water and over cropland. Consistent with a link between foraging habitat and reproductive success, nests in barns with more wetland and less open water within 1 km, and with less field area within 2 km occupied by row crops, on average fledged more young swallows.

Author Keywords: aerial insectivores, automated telemetry, habitat use, land cover, movement, nest success

2018

Habitat use within and among roosts of chimney swifts (Chaetura pelagica)

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Names:
Creator (cre): Farquhar, Melanie Lisa, Thesis advisor (ths): Nocera, Joseph J, Degree committee member (dgc): Nol, Erica, Degree committee member (dgc): Burness, Gary, Degree granting institution (dgg): Trent University
Abstract:

Chimney swifts are listed as Threatened nationally and in many provinces within Canada due to rapid population declines. I examined large-scale spatial variation in the maximum size of chimney swift roosts at the northern edge of their range to identify where larger roosts occur. I used multi-sourced data collected across Ontario and Quebec between 1998 and 2013. I found that larger roosts were found at more northerly latitudes, and that very large roosts (>1000 birds) only occurred north of 45°. I also investigated fine-scale patterns of chimney swift positioning inside one of the largest roosts in Ontario. Using digitally recorded images, I calculated the angular position of swifts inside the roost relative to ambient and roost temperature. I found that swifts showed a strong preference for clinging to the south facing wall and clustered more when ambient air temperature was warmer. Thus, huddling in swifts provides additional or alternate benefits, other than serving purely to reduce costs of thermoregulation at low ambient temperatures. This research contributes to the understanding of chimney swift roosting ecology and identifies large roosting sites that should be retained for conservation.

Author Keywords: chimney swift, communal roosting, conservation, group size, social thermoregulation, species-at-risk

2018