Female cats, but not males, adjust responsiveness to arousal in the voice of kittens

Abstract

BackgroundThe infant cry is the most important communicative tool to elicit adaptive parental behaviour. Sex-specific adaptation, linked to parental investment, may have evolutionary shaped the responsiveness to changes in the voice of the infant cries. The emotional content of infant cries may trigger distinctive responsiveness either based on their general arousing properties, being part of a general affect encoding rule, or based on affective perception, linked to parental investment, differing between species. To address this question, we performed playback experiments using infant isolation calls in a species without paternal care, the domestic cat. We used kitten calls recorded in isolation contexts inducing either Low arousal (i.e., isolation only) or High arousal (i.e., additional handling), leading to respective differences in escape response of the kittens. We predicted that only females respond differently to playbacks of Low versus High arousal kitten isolation calls, based on sex-differences in parental investment.ResultsFindings showed sex-specific responsiveness of adult cats listening to kitten isolation calls of different arousal conditions, with only females responding faster towards calls of the High versus the Low arousal condition. Breeding experience of females did not affect the result. Furthermore, female responsiveness correlated with acoustic parameters related to spectral characteristics of the fundamental frequency (F0): Females responded faster to kitten calls with lower F0 at call onset, lower minimum F0 and a steeper slope of the F0.ConclusionsOur study revealed sex-specific differences in the responsiveness to kitten isolation calls of different arousal conditions independent of female breeding experience. The findings indicated that features of F0 are important to convey the arousal state of an infant. Taken together, the results suggest that differences in parental investment evolutionary shaped responsiveness (auditory sensitivity/ motivation) to infant calls in a sex-specific manner in the domestic cat.Electronic supplementary materialThe online version of this article (doi:10.1186/s12862-016-0718-9) contains supplementary material, which is available to authorized users.

Immunoecology of species with alternative reproductive tactics and strategies

“…In several immunological studies in species with ARTS, the hypotheses and predictions are not clearly articulated. Males and females are dissimilar in so many ways that it is not surprising to find one more difference (e.g., Konerding et al, 2016). Differences between the 2 sexes could be predicted using relatively weak arguments, but if differences are found, there is no way of really knowing whether they indeed support a particular hypothesis.…”

The head turn paradigm to assess auditory laterality in cats: influence of ear position and repeated sound presentation

“…We expected a shift to a left ear preference (i.e., more left than right head turns) for high compared to low arousal calls in female cats only. As males showed no behavioral differences between either arousal categories ( Konerding et al, 2016 ) we expect them to show the typical right ear/left hemispheric dominance to both types of this species-specific vocalization.…”

“…In our previous publications, we already showed that kitten isolation calls show changes in acoustic properties during low versus high arousal behavioural conditions ( Scheumann et al, 2012 ) and that these differences in conveyed arousal induced concordant differences in responsiveness in female cats ( Konerding et al, 2016 ). Thereby, females oriented significantly faster towards the sound-source to high versus low arousal kitten calls.…”

“…We tested 15 adult cats (eight males, seven females) aged one to eight years (mean m = 2.6, mean f = 3.3). Housing conditions were the same, as described in Konerding et al (2016) . All subjects were not neutered/ castrated and originated from and were kept at the breeding facility of the Central Animal Facility of the Hannover Medical School.…”

“…To assess the impact of induced arousal on the lateralization of conspecific calls, we investigated potential differences in head turn direction toward these two call categories. These calls did only differ in a defined set of acoustic parameters, related to the arousing property of the eliciting behavioural situation ( Scheumann et al, 2012 ) and have been found to influence the urgency to respond in female but not male cats ( Konerding et al, 2016 ). We expected a shift to a left ear preference (i.e., more left than right head turns) for high compared to low arousal calls in female cats only.…”