Removal of adult males from the rearing environment increases preference for same-sex partners in the zebra finch

The developmental processes producing preferences for opposite-sex mating p artners are not well understood. Zebra finches, Taeniopygia guttata, are co lonial and socially monogamous with biparental care. To determine whether t he early social environment contributes to sexual partner preference, we re moved adult males from breeding colonies when the oldest chicks were less t han 1 week old (male-removal rearing) or left them in the breeding cage (co ntrol rearing). At independence, male-removal and control offspring were mo ved to unisex cages. As adults they were given two-choice tests with male v ersus female stimuli followed by group aviary tests. Male-removal subjects, unlike controls, did not prefer opposite-sex stimuli in the two-choice tes ts. Male-removal subjects were less likely than controls to successfully pa ir with opposite-sex birds in the group aviary tests; 38% of them paired wi th a same-sex bird. Thus early social experience may contribute to a critic al component of mate choice, choosing the opposite sex, in this pair-bondin g species. (C) 2000 The Association for the Study of Animal Behaviour.