Supersize me: hypotheses on torpor-assisted prehibernation fattening in a boreal bat.
Biol Lett
; 20(9): 20240291, 2024 Sep.
Article
in En
| MEDLINE
| ID: mdl-39288816
ABSTRACT
Hibernators face an energetic dilemma in the autumn at northern latitudes; while temperatures and food availability decrease, hibernating species need to build fat deposits to survive the winter. During this critical fattening phase, insectivorous boreal bats use torpor to build and conserve their reserves. However, we still know little about temporal variability in torpor use employed by bats during the prehibernation fattening period and how decreasing temperatures and food availability in combination with increasing individual body mass impact this. Here, we present two general hypotheses for explaining temporal torpor patterns observed in a boreal bat (Eptesicus nilssonii), in which torpor use (i) facilitates rapid mass gain or (ii) conserves stored body mass. Although temporally separated in our dataset, data on temperature, insect abundance and body mass throughout the prehibernation period indicate that E. nilssonii reaches the majority of its overwintering mass before the onset of increasing daytime and night-time torpor use. In combination with low food availability by this point in time, these observations suggest torpor expression may be intended to conserve gained reserves rather than facilitate mass gain. Our study is intended as a first proof of concept for disentangling temporal drivers of torpor in bats during the prehibernation fattening phase.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Chiroptera
/
Torpor
/
Hibernation
Limits:
Animals
Language:
En
Journal:
Biol Lett
Journal subject:
BIOLOGIA
Year:
2024
Document type:
Article
Affiliation country:
Finland
Country of publication:
United kingdom