Mothers' fear of human affects the emotional reactivity of young in domestic Japanese quail

The aim of this study was to determine whether mothers' fear of human could influence the way young domestic Japanese quail respond to human. The first step was to obtain a set of adoptive mothers habituated-to-human (H mothers) and a set of adoptive mothers non-habituated-to-human (NH mothers). A set of 6-month-old adult females was handling daily for 15 successive days whereas another set of 6-month-old adult females received no visual or physical contact with human during the same period. We then obtained two sets of adoptive mothers non-divergent in tonic immobility (TI) duration but divergent by the amount of "fear" behaviour expressed towards human (human observer test, cage-plus-experimenter test). Then, we compared a set of young raised by H mothers to a set of young raised by NH mothers. Observations and tests were carried out both during the brooding period (between 5 and 12 days of age) and after separation from mothers (between 13 and 90 days of age). Our results revealed that young raised by H mothers were less fearful towards a static human (cage-plus-experimenter test, hand-on-home-cage-door-test) as well as towards a moving human (human observer test and capture test) than young raised by NH mothers. Nevertheless, as was found between the two sets of adoptive mothers, no clear differences were found between the two sets of young concerning general emotional reactivity (tonic immobility test, open field test and hole-in-the-wall test). These results reveal that young bird's emotional reactivity to human could be modulated by the mother and that this maternal influence remains detectable well after the end of maternal contact. (C) 2004 Elsevier B.V. All rights reserved.