An experience to remember: lifelong effects of playback-based trapping on behaviour of a migratory passerine bird
Abstrakt
Ringing is one of the most commonly used techniques to monitor bird individuals and collect data on various aspects of their life history. However, this method involves practices (capturing and handling) that might affect individuals' behaviour.
Wild animals can remember and learn from previous experiences, and, thus, they anticipate risks and modify their response in subsequent similar situations. In this study, we aimed to evaluate the long-term effects of playback-associated mist netting on the behaviour of the tawny pipit, Anthus campestris, a medium-sized migratory passerine bird.
In playback experiments simulating territorial intrusion of a conspecific male, we examined aggressive responses of individuals attracted in the past by conspecific song playback to a mist net ('experienced' males) and compared them to the responses of individuals without such an experience ('naive' males). The interval between the capture of experienced males and the playback experiments ranged from several weeks to more than 5 years.
Our results revealed prominent differences between the behaviour of naive tawny pipit males and those experienced with a capturing event. Although all tested males responded to the stimulus, experienced males tended to be substantially less aggressive and more cautious in comparison to naive individuals; prominent differences were observed, in particular, in the avoidance of close proximity to the loudspeaker by the majority of experienced males.
There were no significant differences in responses to playbacks between the experienced males captured and exposed to subsequent experiments within the same or next season and those that underwent playback experiments later, up to 5 years after having been previously trapped. These findings suggest that male tawny pipits may negatively associate playback stimulation with capturing events and remember such experiences over a time period comparable to the expected life span of this species in the wild.