No energetic benefits from sociality in tropical hibernation. (15th November 2014)

• Record Type: Journal Article
• Authors: Dausmann, Kathrin H.; Glos, Julian; Franklin, Craig
• Is Part Of: Functional ecology. Volume 29:Number 4(2015:Aug.)
• Page Start: 498
• Page End: 505
• Publication Date: 2014-11-15
• Subjects: Ecology -- Periodicals; 574.505
• DOI: 10.1111/1365-2435.12368
• Languages: English
• ISSNs: 0269-8463

Abstract

<abstract abstract-type="main" id="fec12368-abs-0001"> <title>Summary</title> <p> <list id="fec12368-list-0001" list-type="order"> <list-item> <p>Mammals generally profit from social thermoregulation, and the primary benefit of sociality during hibernation is thought to be the reduction of metabolic demands during periodic arousals. It has even been postulated that the energetic advantages during hibernation might have been the driver for the evolution of sociality in some mammal species.</p> </list-item> <list-item> <p>As the necessity to show arousals and the concurring energetic costs depend on the temperature regime in the hibernacula, we tested whether this is also a plausible scenario in tropical hibernators such as the Malagasy lemur <italic>Cheirogaleus medius</italic>, with comparatively high and often fluctuating temperature regimes in their hibernacula.</p> </list-item> <list-item> <p>To this end, we studied group composition and energy budgets (skin temperature patterns, metabolic rate) over three hibernation and activity seasons in a total of 53 free‐ranging <italic>C. medius</italic>.</p> </list-item> <list-item> <p>Our results show that <italic>C. medius</italic> mostly occupied tree hollows solitarily during hibernation, contrary to the active season, and that the energetic savings were comparable for individuals hibernating socially in groups or solitarily (both about 74% compared to the resting metabolic rate of the active season). However, in larger groups, hibernation patterns were less regular and synchronized and individual torpor–arousal cycles were more frequently interrupted by euthermic group members than in individuals hibernating solitarily or in pairs.</p> </list-item> <list-item> <p>We conclude that sociality during hibernation is not necessarily driven by energetic demands and might even be energetically disadvantageous in tropical species (at least in larger groups). Other factors, like social coherence or ecological and behavioural constraints, may be of greater influence for the evolution of sociality under tropical conditions.</p> </list-item> </list> </p> </abstract>