Photoperiodic and endocrine control of social proximity behavior in male Japanese quail (Coturnix coturnix japonica).

Previous research had shown that reproductively mature male Japanese quail maintained on a 16:08 light/dark (16L:8D) photoperiod spend about 75% of their time throughout daylight hours near a window that provides visual access to a female conspecific. In contrast, females do not display a corresponding tendency to remain near male conspecifics. In Experiment 1, I demonstrated that the social proximity behavior of male Japanese quail declines significantly when photostimulation is restricted to 2 hr daily (02:22 light dark; 2L:22D), but can be restored by reinstituting the 16L:8D schedule. Changes in the photoperiod produced corresponding changes in the size of the cloacal gland, and androgen-dependent organ. The low levels of social proximity behavior and cloacal gland size of males maintained on short daily exposures to light (2L:22D) also could be reversed by sc implants of testosterone (Experiment 2), and this recovery was to some extent sensitive to testosterone dose (Experiment 3). The present studies indicate that social proximity behavior in male Japanese quail is androgen dependent and provide a behavioral assay for neurohormonal studies of sexual behavior that does not depend on brief phasic responses.