Experienced males modify their behaviour during playback: the case of the Chaffinch

This is the authors' abstract. We don't add key points for this paper.

Animals are able to learn, remember, and make use of previous experiences when making decisions in similar situations, which are some of the most fascinating phenomena in behavioural ecology. However, these cognitive abilities can act as impediments for biologists and ecologists when conducting field studies. Experienced animals may significantly modify their behaviour in subsequent interactions, which could lead to incorrect interpretations of the results of experimental or observational studies of such individuals. In this study we examined whether experienced (lured by playback, caught in a mist net, and handled) Chaffinch males (Fringilla coelebs) modified their behaviour during a subsequent playback experiment in comparison with naive males that had not experienced human contact. We examined 46 individuals, and found that, after experiencing capture and playback, Chaffinch males modified their responses during a playback experiment, at least on a short-term basis. Experienced males modified their vocal behaviour during simulated intrusion within their territory, responding predominantly with calls, while control naive males used mostly territorial songs. We suggest that the higher use of calls by experienced males was a result of their previous negative experience and reflected higher levels of anxiety. The differences in response toward playback between experienced and naive males suggest that special attention must be paid to planning, conducting, and analysing studies when performing multiple experiments on the same group of individuals.