Attention grabbing in red deer sexual calls

Identifying the respective functions of distinct call types is an important step towards understanding the diversification of mammal vocal repertoires. Red deer (Cervus elaphus) stags give two distinct types of roars during the rut, termed ‘common roars’ and ‘harsh roars’. This study tests the hypothesis that harsh roars function to raise and maintain female attention to calling males. To this end, we examined the response of female red deer to playback sequences of common roar bouts including a bout of harsh roars midway through the sequence. We found that females not only substantially increased their attention to the bout of harsh roars but also then maintained overall higher attention levels to subsequent common roar bouts. Our results suggest that the specific acoustic characteristics of male red deer harsh roar bouts may have evolved to engage and maintain the attention of female receivers during the breeding season. More generally, they indicate a possible evolutionary path for the diversification of male sexual vocal repertoires.     

Using a new video rating tool to crowd-source analysis of behavioural reaction to stimuli

Animal Cognition - Quantifying the intensity of animals’ reaction to stimuli is notoriously difficult as classic unidimensional measures of responses such as latency or duration of looking...     

Grey wolves (Canis lupus) discriminate between familiar and unfamiliar human voices

Animal Cognition - The ability to discriminate between different individuals based on identity cues, which is important to support the social behaviour of many animal species, has mostly been...     

Control of voice gender in pre‐pubertal children

Adult listeners are capable of identifying the gender of speakers as young as 4 years old from their voice. In the absence of a clear anatomical dimorphism in the dimensions of pre‐pubertal boys' and girls' vocal apparatus, the observed gender differences may reflect children's regulation of their vocal behaviour. A detailed acoustic analysis was conducted of the utterances of 34 6‐ to 9‐year‐old children, in their normal voices and also when asked explicitly to speak like a boy or a girl. Results showed statistically significant shifts in fundamental and formant frequency values towards those expected from the sex dimorphism in adult voices. Directions for future research on the role of vocal behaviours in pre‐pubertal children's expression of gender are considered.