Effects of genetic selection for fearfulness or social reinstatement behavior on adult social and sexual behavior in domestic quail (Coturnix japonica)

Male quail (Coturnix japonica) were genetically selected for high or low levels of social reinstatement behavior (weighted for independence from inherent fearfulness) and high or low fearfulness (weighted for independence from social reinstatement behavior). Genetic selection was based on tests conducted during the first 10 days after hatching. Inherent fearfulness was inferred from a test of the tonic immobility response, and social reinstatement behavior was measured in a treadmill test. When tested in adulthood, males selected for high levels of social reinstatement behavior showed more social proximity behavior, shorter latencies to copulate with a female, larger numbers of copulatory responses, and greater copulatory efficiency than did males selected for low inherent fearfulness. The other genetic lines performed at intermediate levels. Thus, the effects of genetic selection extended into adulthood and influenced responses that were not in the behavioral repertoire of the birds at the time of selection. Interestingly, selection for inherent fearfulness did not necessarily disrupt sexual performance. In fact, fearfulness appeared, at least to some extent, to be conducive to the expression of male sexual behavior.