A comparative analysis of huddling in infant Norway rats and Syrian golden hamsters: does endothermy modulate behavior?
In infant rats, huddling improves surface-to-volume ratios and provides metabolic savings during cold exposure. It is unclear, however, whether endothermy is also a necessary component of huddling. In the present experiment, huddles composed of infant Norway rats (2- or 8-day-olds), which produce heat endogenously, or Syrian golden hamsters (8-day-olds), which do not produce heat endogenously, were exposed to decreases in air temperature. Behavioral and physiological responses were monitored throughout the test. Rats, especially at 8 days of age, were better able to thermoregulate using huddling than hamsters, due in part to endogenous heat production. Furthermore, 8-day-old rats exhibited behavioral responses that promote heat retention, suggesting that both physiological and behavioral mechanisms contribute to effective thermoregulation during huddling in the cold.
Sokoloff
G
G
Department of Psychology, University of Iowa, Iowa City 52242, USA. greta-sokoloff@uiowa.edu
Blumberg
M S
MS
Adams
M M
MM
D002001:Adipose Tissue, Brown / Q000502:physiology; D000818:Animals; D000831:Animals, Newborn / Q000502:physiology*; D001833:Body Temperature Regulation / Q000502:physiology*; D006224:Cricetinae; D004734:Energy Metabolism / Q000502:physiology; D008647:Mesocricetus; D010101:Oxygen Consumption / Q000502:physiology; D051381:Rats; D012931:Social Environment; D014828:Vocalization, Animal / Q000502:physiology