Sexual preferences for mate song types in female song sparrows

Copulation solicitation displays were used to investigate whether female song sparrows are especially stimulated by the songs their mates sing. Eight of nine (88.9%) recently captured oestradioltreated female song sparrows, Melospiza melodia, gave more solicitation displays and displayed more intensely for song types recorded from repertoires of their mates than for songs from other males from the local population. This is the first study to show female sexual preferences for mate song in songbirds and to demonstrate that female song sparrows discriminate in their sexual responses based on song types. It is not known whether these song preferences influenced females’ choice of mate in the field or arose after pair formation. Regardless of origin, especially stimulating songs are likely to be important to the reproductive behaviour of females and could influence the mating success of males. ? 1997 The Association for the Study of Animal Behaviour It is generally accepted that one of the functions of song in male songbirds is attraction and stimulation of a mate (Searcy & Andersson 1986; Catchpole 1987; Kroodsma & Byers 1991). Evidence to support this assumption includes results from a number of laboratory studies that used the copulation solicitation displays adopted by females of some species in response to recorded song (Searcy 1992a). In most species studied to date using this procedure, females have shown sexual preferences for certain categories of song and in general, have been more responsive to speciesand populationtypical conspecific songs (King & West 1977; Baker et al. 1981; Searcy & Marler 1981; O’Loghlen & Rothstein 1995). The discrimination shown by females under these laboratory conditions is likely to be important in nature because these preferences are expressed in a direct mating context (Searcy 1992a). Thus males whose singing behaviour is especially sexually stimulating for females are likely to enjoy some reproductive advantage. Studies of Acrocephalus warblers and of brown-headed cowbirds, Molothrus ater, have provided experimental evidence to support this conclusion (Catchpole 1987;