Place preferences of Japanese quail given a permanent choice between a social or a non-social but enriched situation.

Japanese quail from two lines selected for high (HSR) or low (LSR) levels of social reinstatement behaviour were permanently placed from 2 days to 6 weeks of age in a situation where one tested animal had the choice between being in social contact with a stimulus animal in a bare compartment of the cage or out of visual contact with the stimulus animal in a relatively rich environment containing food, water and wood shavings. The young (1 or 2 weeks of age) quails spent most of their time (over 80%) in the social compartment, about 10% feeding and drinking, and about 10% performing other activities in the non-social compartment. Hardly any differences appeared between the two lines when 1 or 2 weeks old, but at 4 weeks of age the LSR quails started to decrease the time spent in the social compartment and this phenomenon only appeared at 6 weeks of age and to a lesser extent in the HSR quails. At 4 and 6 weeks the differences between lines were significant. The lack of difference between the two lines in young quails can be explained by the very high social motivation expressed even by LSR quails in the conditions of the study. When they are older line differences are expressed. This change coincides with the time when the natural coveys start to disperse and also with the beginning of sexual development. These results confirm the hypothesis of François et al. (François, N., Mills, A.D., Faure, J.M., 1997. Inter-individual distances in Japanese quail (Coturnix japonica) selected for high or low levels of sociability. Behav. Process. (in press)) that line differences in social motivation persist into adult or near adult life and can still be demonstrated, provided the circumstances are such that aggression does not prevent close social contact.