Isolation calls in house mouse pups: individual consistency across time and situations

Abstract

Isolation calls are emitted by the offspring of many mammals when separated from caregivers and siblings. Recent studies indicated that isolation call rates constitute a consistent individual trait, although the young might also modulate their call rate depending of the immediate situation. We studied in the house mouse whether individual differences in pup isolation call rate were stable across time, thus fulfilling the condition of a consistent individual trait, aand whether and how call rates were modulated by 3 social situations, experimentally induced after an initial isolation: (1) a reunion with mother and littermates followed by a second isolation, (2) the confrontation of the isolated pup with odor cues of its own nest or (3) with odor cues of an unfamiliar adult male. The first treatment induced an increase while the others decreased the number of calls. Pups showed consistent individual differences in initial isolation call rates, which were associated with individual differences in call rate changes during the 3 social situations. We conclude that isolation calls represent a trait-like behavior which can also express flexibility in response to novel social situations.

Full text

Isolation calls in house mouse pups:
individual consistency across time and situations
Aurélie Verjat, Heiko G. Rödel, Christophe Féron
Laboratoire d’Ethologie Expérimentale et Comparée E.A. 4443 (LEEC), Université Paris 13, Villetaneuse,
France
Abstract: Isolation calls are emitted by the offspring of many mammals when separated from
caregivers and siblings. Recent studies indicated that isolation call rates constitute a consistent
individual trait, although the young might also modulate their call rate depending of the immediate
situation. We studied in the house mouse whether individual differences in pup isolation call rate
were stable across time, thus fulfilling the condition of a consistent individual trait, aand whether
and how call rates were modulated by 3 social situations, experimentally induced after an initial
isolation: (1) a reunion with mother and littermates followed by a second isolation, (2) the
confrontation of the isolated pup with odor cues of its own nest or (3) with odor cues of an
unfamiliar adult male. The first treatment induced an increase while the others decreased the
number of calls. Pups showed consistent individual differences in initial isolation call rates, which
were associated with individual differences in call rate changes during the 3 social situations. We
conclude that isolation calls represent a trait-like behavior which can also express flexibility in
response to novel social situations.