Direct and correlated responses to bidirectional selection for dustbathing activity in Japanese quail (Coturnix coturnix japonica).

Bidirectional selection was conducted for dustbathing activity in male Japanese quail over 17 generations. The response to selection was slightly asymmetrical, due mainly to scale effects and a threshold imposing discontinuity on the visible expression of dustbathing in the low line. Correlated responses to selection were found for latency to dustbathe, duration, intensity, and incidence of nonbathers. In general, changes followed linear patterns over time in both lines with the exception of quadratic change in nonbathers in the high line. Under artificial environment, only minor natural selection pressure is assumed to act on the expression of dustbathing behavior.