Journal
NATURWISSENSCHAFTEN
Volume 97, Issue 1, Pages 29-35Publisher
SPRINGER
DOI: 10.1007/s00114-009-0606-x
Keywords
Body condition index; Chiroptera; Insectivorous; Nyctophilus; Predator avoidance; Torpor
Categories
Funding
- University of New England and Bat Conservation International to CS
- Australian Research Council
Ask authors/readers for more resources
A widely held view is that torpor is avoided by mammals whenever possible because of potential costs associated with reduced body temperatures and slowed metabolic processes. We examined this hypothesis by quantifying use of torpor in relation to body condition of free-ranging northern long-eared bats (Nyctophilus bifax, approximately 10 g), a species known to hibernate, from a subtropical region during the austral summer when insects were abundant. Temperature-telemetry revealed that bats used torpor on 85% of observation days and on 38% of all nights. Torpor bouts ranged from 0.7 to 21.2 h, but the relationship between duration of torpor bouts and ambient temperature was not significant. However, skin temperature of torpid bats was positively correlated with ambient temperature. Against predictions, individuals with a high body condition index (i.e., good fat/energy reserves) expressed longer and deeper torpor bouts and also employed torpor more often during the activity phase at night than those with low body condition index. We provide the first evidence that use of torpor in a free-ranging subtropical mammal is positively related with high body condition index. This suggests that employment of torpor is maximised and foraging minimised not because of food shortages or low energy stores but likely to avoid predation when bats are not required to feed.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available