You are encouraged to attend the defence. You are encouraged to attend the defence. The details of the defence and attendance information is included below: 

Date: 09 August 2024

Time: 9:30 AM (PT)

Defence mode: Remote

Virtual Attendance: Zoom

LINK TO JOIN: Please contact the Office of Graduate Administration for information regarding remote attendance for online defences.

To ensure the defence proceeds with no interruptions, please mute your audio and video on entry and do not inadvertently share your screen. The meeting will be locked to entry 5 minutes after it begins: ensure you are on time. 

Thesis entitled: EFFECTS OF LANDSCAPE CHANGE ON COW MOOSE BODY FAT AND PHYSIOLOGY IN CENTRAL BRITISH COLUMBIA

Abstract: Forest harvesting affects wildlife in complex ways, including through changes in the nutritional, thermal, and protective properties of habitat. Understanding the mechanisms by which wildlife respond to changes in habitat is therefore necessary to identify beneficial characteristics to be protected or restored. This is particularly important given compounding effects of climate change, which can interact with habitat change to alter the thermal and nutritional environment experienced by wildlife. Physiological bioindicators that reflect endocrine activity and nutrition are one approach to identify the importance of multiple potential mechanisms by which wildlife respond to environmental change.

I used multiple bioindicators measured in cow moose (Alces alces) at capture and through non-invasive sampling to evaluate moose response to forest harvesting in central British Columbia (BC). Over the past two decades, moose in central BC have experience dramatic declines. Findings from the BC Provincial Moose Research Project found evidence of nutritional deficiencies in moose, potentially associated with increased forest harvesting associated with the mountain pine beetle epidemic that has occurred over the same time period. My thesis focuses on the knowledge gap related to specific mechanisms linking forest harvesting with poor nutritional condition in moose.

First, I tested hypotheses that hair cortisol and body fat in cow moose would be associated with nutritional, thermal, and/or predation risk characteristics of summer habitat. I used hair samples and body fat measurements collected at capture and general linear mixedeffects models. I found that 50% of moose had body fat levels below 9%, which is considered indicative of poor nutrition. Hair cortisol was higher in moose that experienced warmer summer home range temperatures and decreased when summer home ranges had a higher proportion of mature conifer forest, providing thermoregulatory refuge. Cows with calves, compared to those without, had lower body fat, suggesting that nutrition, predation risk, thermal conditions, nor anthropogenic disturbances influence moose physiology more than the energetic costs of lactation.

Secondly, I used non-invasive measures of physiology to understand how cow moose respond to disturbance, predation, habitat characteristics, and environmental conditions in winter. I found that temperature was the most important predictor of urea nitrogen: creatine concentrations, supporting evidence that warm thermal conditions in winter limit the energy profile of moose. Fecal cortisol was higher in moose that used mature conifer stands, potentially reflecting the low nutritional value of this habitat type. Fecal triiodothyronine levels were higher in moose that recently used mid-seral stands, indicating increased energetic intake.

Collectively, my findings highlight that for a cold-adapted species such as moose, physiological processes alone may prove inadequate to withstand both nutritional deficits and thermal energetic costs endured by moose in fragmented landscapes. The physiological capacity to withstand these pressures is likely linked to the availability of mature stands. I conclude that thermal stress is the most important parameter influencing the physiological state of moose and that it is one mechanism contributing to health-related mortalities. Moose stand to benefit from forest management that maintains thermal shelter and implements silviculture prescriptions that promotes static foraging opportunities in perpetuity.

Examining Committee: 

Chair: Dr. Catharine Schiller, University of Northern British Columbia 

Supervisor: Dr. Heather Bryan, The University of Northern British Columbia 

Committee Member: Dr. Jeffery Werner, The University of Northern British Columbia 

Committee Member: Dr. Morgan Anderson, BC Ministry of Forests

Committee Member: Dr. Roy Rea, The University of Northern British Columbia

External Examiner: Dr. Shelley Marshall, BC Ministry of Forests