| Summary: | Determining the contexts of emission and information content of vocal signals can yield insights into the function of different call types, and remains an important step towards understanding the diversification of mammalian vocal repertoires. In this study, we used infra-red video cameras and remote audio recorders to document seasonal and contextual variation in male European badger (Meles meles) churr production over a 24-month period, and acoustic analysis based on source-filter theory to examine whether churr acoustic structure varies according to the caller’s arousal state and identity. Our behavioural observations revealed that male churrs are produced almost exclusively during the breeding season. Further contextual analysis showed that males emit churrs during close-range interactions with female conspecifics, often during copulation attempts, and churr directly into sett entrances. In addition, males involved in close-range social interactions delivered churrs with more call units per second than those vocalising without other conspecifics in close proximity. Discriminant function analysis also revealed that male churrs are individually distinctive, and confirmed that the formants (vocal tract resonances) contribute the most to caller identity. These findings indicate that badger churrs are sexual calls with the potential to signal male arousal state and identity in reproductive contexts. They also add to an increasing body of literature on the importance of formants for identity cueing in nonhuman mammals.
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