Gathering public information for habitat selection: prospecting birds cue on parental activity.

Because habitat quality strongly affects individual fitness, understanding individual habitat selection strategies is fundamental for most aspects of the evolution and conservation of species. Several studies suggest that individuals gather public information, i.e. information derived from the reproductive performance of conspecifics, to assess and select habitats. However, the behavioural mechanisms of information gathering, i.e. prospecting, are largely unknown, despite the fact that they directly constrain individual selection strategies. To test whether prospectors gather public information or other cues of habitat quality, we manipulated brood size of collared flycatchers (Ficedula albicollis) and investigated subsequent attraction of prospectors. Experimentally adding two nestlings increased the probability of attracting prospectors to the nest as a result of increased parental feeding rates. Prospectors were attracted to the most successful sites because feeding rate predicted subsequent fledgling production. In the year following prospecting, individuals selected a breeding site very close to the prospected site. These results provide the first experimental evidence, to our knowledge, of the links between information gathering behaviour and breeding habitat selection strategies based on public information.