Sexual preferences of male zebra finches:Effects of early and adult experience

Sexual preferences of male zebra finches develop under the influence of early social experience and are assumed to be stable in adults. The present study examines whether adult experience can modify effects of early experience. Male zebra finches, Taeniopygia guttata castanotis, were raised by Bengalese finch, Lonchura striata, foster parents for 40 days. As adults, males were given choice tests between a zebra finch and a Bengalese finch female. In a two by two design, the effects of breeding experience with a conspecific female and those of choice tests given prior to breeding were examined. Breeding experience shifted preferences in the direction of zebra finches, but much less so in previously tested males than in males that were not tested before the breeding experience. The shift was not completely stable. However, the difference between previously tested and untested males continued to exist for over 1 year. Breeding success and extent of shift were not related. Another group of males, which received no prior choice tests as adults and were exposed to a zebra finch female but were separated from her by wire, showed in subsequent choice tests a shift of preference to zebra finches that did not differ from males that were treated similarly but received breeding experience. The results suggest that short exposure to a preferred female leads to consolidation of earlier acquired preferences. However, much longer exposure to a non-preferred female either in a breeding situation, or through wire, leads to considerable modification of preferences of adult zebra finch males. The effects of both processes are maintained for at least 1 year. The results are discussed in relation to current views on imprintin