Individual Life History and Song Repertoire Changes in a Colony of Starlings (Sturnus vulgaris)
Résumé
Observations were made over two years in a small colony of starlings to look at possible changes in the songs of each male, taking into account its life-history and breeding status. Each male sings two categories of song: warbling, a long, complex and mainly individual song, and loud and simple whistles. Within the latter, some are species-specific whereas others characterize the individual in its colony. Over two years very few changes were observed for the species-specific whistle themes and all birds shared the same variant. But the birds changed their individual whistle types almost completely from one year to the next. Changes in warbling song may depend on age: one bird changed his repertoire of motifs completely between his first and second year of life, whereas other older males merely added some new motifs to their repertoire of the previous year. Such results show that adult starlings in the wild, even older birds (7 years old), may still be able to acquire new structures. The new elements appeared in the fall and were kept at least until the following breeding season. All songs were very stable throughout a given breeding season. Although individual repertoires increased with age, large differences in repertoire size were found in same age individuals. First data suggest that breeding status (e.g. polygyny) and repertoire size may be related.