We investigated whether contrasting T-maze behaviour shown by domestic chic
ks, Gallus gallus domesticus, of a broiler strain reflected underlying diff
erences in their general activity levels, fearfulness or sociality. The tim
e taken by 2-day-old chicks to traverse a T maze and thereby regain visual
contact with their companions was measured. Chicks were categorized accordi
ng to whether they completed this task quickly (HP, high performance, <25 s
) or slowly (LP, low performance, >75 s) and then housed in same-category g
roups, each of eight chicks. In experiment 1, we compared the numbers of HP
and LP chicks showing certain home cage behaviours (ambulation, standing,
resting, maintenance, pecking, preening). No significant differences were f
ound. In experiment 2, we compared the behaviour of HP and LP chicks in two
tests of sociality (homecage proximity, runway) and in two tests of fear (
emergence, tonic immobility). The HP chicks stayed closer together in the h
ome cage than did their LP counterparts and they spent significantly longer
near a goal;box containing conspecifics in the runway than did LP ones. Co
nversely, there were no significant differences between HP and LP chicks in
their latency to emerge from a sheltered area into an exposed and, hence,
potentially frightening one or in their tonic immobility fear reactions. Th
ese findings suggest that;contrasting T-maze performance was unlikely to ha
ve reflected differences in underlying activity levels or in fearfulness. C
onversely, individual variation in underlying sociality was probably an inf
luential variable. (C) 1999 The Association for the Study of Animal Behavio
ur.