Season-dependent processing of innate conspecific vocalizations in the male and female European starling (Sturnus vulgaris)

Avian innate nestling begging calls are similar to human infant cries in the behavioral response they elicit. However, it remains unknown whether the auditory processing of innate begging calls changes in seasonal songbirds from non-breeding to breeding season when hormonal neuromodulation of the auditory forebrain occurs. An fMRI experiment was set up to expose male and female European starlings (Sturnus vulgaris) to recordings of seasonal conspecific nestling begging calls in the breeding and non-breeding season. This response was compared with their response to conspecific warble motifs and artificial pure tones, both proven seasonally invariable at least in the male starlings neural response. Our results demonstrate significant seasonal variation in auditory forebrain responses exclusively elicited by begging calls and not by the applied control stimuli. Right Field L and the Caudomedial Nidopallium (NCM) seemed, irrespective of season or sex, more sensitive in response to begging than to control stimuli. A seasonal differential response specifically to begging calls was found in both sexes in a ventral midsagittal region of NCM. Our findings thereby support the functional fine-tuning of vocal communications between sender and receiver in a breeding context for innate vocalizations and are in line with the bi-parenting behavior in this species.