Bioenergetics of a Covey of Bobwhites

Existence energy requirements of a covey of eight females were measured and compared with those of the same eight females individually confined. The roosting formation generally was more compact at cold than at warm temperatures; huddling provided a metabolic advantage at 5°C but became energetically disadvantageous at higher temperatures. Occasionally tight roosting circles were observed at warm temperatures, when the behavior was seemingly metabolically disadvantageous. Analyses of differences in energy requirements of individuals and covey resulted in a departure from linearity between 10 and 20°C, which presumably represented a shifting LCT (manifested by different temperatures of acclimation and a concomitant lower feeding level). The adaptive significance of covey behavior when temperatures are warm enough to confer a seemingly metabolic disadvantage may be associated with proximate and ultimate factors. Ultimately the behavior is concerned with energy conservation, but the proximate control (which would be other than temperature) could be photoperiod. Roosting disks may also have an adaptive advantage in regard to predation.