Microgeographic variation, habitat effects and individual signature cues in calls of chiffchaffs Phylloscopus collybita canarensis

Variation of signals is a widespread feature in animal communication. Signa ls usually vary among signallers and in some cases vary across geographic a reas. Individual variation provides the basis for individual recognition an d thus has important implications for social interactions. Microgeographic variation can reveal insights into patterns of dispersal and into timing an d mechanism of acquisition or development of behavioral traits. In addition , it may reflect adaptations of signals to the transmission characteristics of local habitat types. In song birds these kinds of variation have been d ocumented in particular for male song. Here, we examined individual signatu re cues, site-specific variation, and variation among habitat types in tona l contact calls of 26 chiffchaffs, Phylloscopus collybita canarensis, recor ded on two Canary islands. Multiparametric analyses of calls and subsequent discriminant function analyses revealed clear individual differences as we ll as microgeographic variation in call structure. Call structures differed not only between islands but also among the different locations on Tenerif e, indicating that individuals on the same island do not share the same cal l, as suggested earlier. Calls recorded in different types of habitat, howe ver, did not differ in structure as predicted by the 'acoustic adaptation h ypothesis'. The findings indicate that individual recognition may be possib le on the basis of calls and they contribute to the understanding of develo pment of behavioural trails in relation to life history patterns such as th e timing and pattern of dispersal.