Data from: Begging blue tit nestlings discriminate between the odour of familiar and unfamiliar conspecifics

1. Offspring often solicit, and compete for, limited parental care by
elaborate begging behaviour. Kin selection theory predicts that competing
offspring should modify the intensity of their begging depending on the
degree of relatedness to their nest- or litter mates. 2. Empirical
evidence in birds, which are a key model in the study of parent-offspring
interactions, indeed indicates that a lower level of relatedness between
offspring in the nest correlates with more intense begging (i.e. more
‘selfish’ behaviour). This implies that competing nestlings can recognize
kin, but the mechanism underlying such discrimination is unclear. Birds
have long been thought to mainly rely on visual and auditory cues in their
social communication, but there is now growing evidence for the importance
of olfactory cues too. 3. To assess the potential importance of olfactory
cues in modulating nestling begging behaviour, we experimentally tested in
a free-living bird, the blue tit Cyanistes caeruleus, if nestlings
discriminate and adjust their begging behaviour depending on their
familiarity with a conspecific nestling odour stimulus. 4. We found that
individuals responded with longer and more intense begging bouts to an
unfamiliar compared to a familiar odour stimulus. 5. Our findings provide
first evidence for a role of olfaction in modulating offspring begging
behaviour in a wild bird population. Although our experiment cannot
differentiate between the effects of familiarity and relatedness, it
raises the interesting possibility that blue tit nestlings may also
discriminate between odours of kin and non-kin, and adjust their begging
behaviour accordingly. This hypothesis requires further testing.

Nestling begging
responses to familiar versus unfamiliar odour stimuliThis data file was used
to analyse the likelihood, duration and intensity of nestling begging
responses to familiar versus unfamiliar odour stimuli, while controlling
for several additional predictor variables.Rossi_FunctEcol_BeggingExperiment.csvNestling mass and survivalThis data file was used to analyse the effect of the olfactory discrimination test trials on nestling mass and survival as observed on day 15 after hatching.Rossi_FunctEcol_NestlingMassSurvival.csv