Bachelor of Science
School or Department
Wildlife Biology – Terrestrial
Faculty Mentor Department
Chad Bishop, Joshua Millspaugh
Ungulate nutritional ecology, body condition, energetic costs of reproduction, topdown vs. bottom-up, individual vs. environmental, elk, neonate predation
Ecology and Evolutionary Biology | Life Sciences
Ungulate body condition is often understood to reflect the nutritional resources on the landscape but is ultimately influenced by more than forage because body condition integrates both energetic costs and benefits. Factors driving variation in female body condition can be classified in both individual vs. environmental and bottom-up vs. top-down frameworks. My research evaluates how individual vs. environmental and bottom-up vs. top-down frameworks explain variation in ingesta-free body fat (IFBF) in female elk (Cervus canadensis). I used seven years (2015-2021) of IFBF data from monitored and recaptured female elk (n = 139) in the Ya Ha Tinda (YHT) population in Alberta, Canada. I determined the best-fitting generalized linear mixed-effects model to explain IFBF as a function of factors in both frameworks. The top model included only prior summer calf survival as a predictor variable, with the second model (DAICc = 1.42) including both prior summer calf survival and average prior summer forage biomass. The final top model predicts that a female elk whose calf survives the previous summer will have 3.28 percent points (95% CI: 2.38, 4.19) lower body fat levels in winter compared to a female elk whose calf did not survive the summer. The importance of prior summer calf survival as an explanatory variable and the large size of its effect indicates that changes in energetic reproductive costs driven by predation influence variation in female body fat more significantly than bottom-up factors like forage in this system and emphasize the importance of individual variation. This research helps scientists and managers interpret variation in ungulate body condition data and understand the important effects of juvenile survival on adult ungulate female body condition in the context of expanding predator communities across North America.
Honors College Research Project
GLI Capstone Project
Bealer, Nicole P., "Understanding the Drivers of Body Condition in Female Elk: Implications for Nutritional Ecology on Changing Landscapes" (2023). Undergraduate Theses, Professional Papers, and Capstone Artifacts. 430.
© Copyright 2023 Nicole P. Bealer