Rodents living in the cold employ both behavioral and physiological mechanisms to achieve thermoregulation. We examined the impact of fur loss on behavioral thermoregulation in cold-challenged Siberian hamsters (Phodopus sungorus). Intact female hamsters exposed to an ambient temperature (Ta) of 5°C increased their general locomotor activity by 50% relative to animals maintained at 23°C. At both Ta's, fur removal resulted in substantial increases in daily food intake (37% and 22% at 5 and 23°C, respectively) but did not affect the amount of locomotor activity; increased food intake after fur loss evidently is not caused by increases in locomotor activity. Furred hamsters housed in groups of three at 5°C consumed 16% less food per day than did singly housed individuals. Fur removal resulted in identical 39% increases in food intake in group- or singly housed animals. Energy savings that accrued from huddling were identical in furred and furless animals; this behavior conserves energy even in the absence of an insulative pelage. The availability of nesting material resulted in an 18% reduction in food consumption in intact animals kept at 5°C. The increase in food intake produced by fur removal was attenuated by ∼80% when furless animals had access to nesting material. Huddling and nest-building behaviors each ameliorate energetic challenges posed by absence of fur; animals that concurrently employ several modes of thermoregulation realize substantial energy savings in the cold.
- Locomotor activity
- Siberian hamster
ASJC Scopus subject areas
- Experimental and Cognitive Psychology
- Behavioral Neuroscience