Effects of test age, line and sex on tonic immobility responses and social reinstatement behaviour in Japanese quail Coturnix japonica.

The tonic immobility (TI) response and social reinstatement (SR) behaviour (as assessed in a treadmill test) were measured in 1, 2, 4, 6 and 10 week old Japanese quail of lines selected for long (LTI) and short (STI) duration of TI weighted for independence from SR behaviour or high (HSR) and low (LSR) levels of SR behaviour weighted for independence from durations of TI. Irrespective of age, LTI line birds had the longest and STI line birds the shortest duration of TI. The duration of TI did not differ between the HSR and LSR lines. Levels of SR behaviour were always higher in HSR line birds than in birds of the LSR line. SR behaviour did differ significantly between the LTI and STI lines and was shown at levels intermediate between those of the HSR and LSR lines although pairwise comparisons of line differences were not necessarily significant. The age and sex of the birds did not influence the duration of TI but levels of SR behaviour were lower at 2 and 4 weeks than at other ages and males showed more SR behaviour than females.