Evaluating the Physiological and Behavioral Responses of Moose (Alces Alces) to Fluctuating Environmental Temperatures

• Main Author: Thompson, Daniel Paul
• Other Authors: Barboza, Perry S, Farley, Sean, Hewitt, David G, Jaques, Scott
• Format: Thesis
• Language: English
• Published: 2021
• Subjects: Alces alces; Alaska; body temperature; homeothermy; moose; thermoregulation
• Online Access: https://hdl.handle.net/1969.1/192396

This study used core body temperature of moose (Alces alces) to evaluate the relationship between moose and their thermal environment. A novel technique to record body temperature was developed by modifying a vaginal implant transmitter which collected continuous body temperature at 5-minute intervals from female moose for up to one year. Using the vaginal temperature loggers, seasonal patterns of daily mean and daily change in core body temperature were established, with higher daily mean body temperature and daily change in body temperature during the summer than during the winter. Furthermore, body temperature of wild moose was elevated 1hr after chemical immobilization (38.9 °C) but returned to baseline levels within 3hr (38.0 °C), whereas captive moose body temperature was not elevated 1hr post immobilization (37.9 °C). Body temperature in wild moose rose above baseline levels and remained elevated from 12 to 48hrs post capture when movement rates were also elevated, possibly as a result of renarcotization from Carfentanil citrate. Following the animal indicator concept, we used large changes in body temperature (≥1.25 °C in 24h; heat response day) to indicate days of physiological tolerance to thermal stressors. Core body temperature, heart rate, respiration rate, rate of heat loss from exhaled air, and skin temperature were measured in female moose during the warm season. Thermal tolerance correlated with high ambient air temperatures from the prior day. At midday, moose exhibited daily minima of body temperature, heart rate and skin temperature that coincided with daily maxima in respiration rate and the rate of heat lost through respiration. Rumen temperature sensors and GPS collars were used to evaluate how behavior influences changes in rumen temperature in moose. Rumen temperature declined with low to moderate movement rates (<318 m • 0.5 hr⁻¹) associated with foraging in all habitats, while rumen temperature increased for quick movement rates (>318 m • 0.5 hr⁻¹). Moose moved more during heat ...