Anita. Behav., 1972,20, 252-258 AN ANALYSIS OF SOCIAL INTERACTIONS IN JAPANESE QUAIL, COTURNIX COTURNIX JAPONICA BY MARGO I. WILSON* & GORDON BERMANT~ University of Califormia, Davis Abstract. Three groups of male Japanese quail participated in daily, 5-min social encounters with other quail. Members of~one group encountered a castrated male; members of the second group encountered a receptive female; and members of the third group encountered a castrated male and a receptive female on alternate days. After 12 days of testing, all experimental males were castrated and observed in twelve more encounters. Daily androgen therapy was then begun and maintained during a third, final set of twelve encounters. The typical mating and 'courtship' sequences were observed in all three groups. The probability of completing the mating sequence was greater in heterosexual than in homo- sexual contacts; this appeared to be due to the behaviour of the mounted, not the mounting, bird. Both sequences were sensitive to androgen levels, as was the area of the cloacal gland. Heterosexual pairs of Japanese quail readily ex- hibit copulatory behaviour when they are tested in appropriate laboratory environments. Beach & Inman (1965) showed that bilateral castration of the male resulted in total cessation of copu- latory contact and immediately related activity within 8 days; sexual behaviour was restored to normal levels within 8 days after the males had been implanted subcutaneously with pellets of testosterone propionate. Selinger & Bermant (1967) investigated the effects of castration and androgen replacement on the behaviour observed when two male quail encountered each other in a small enclosure. The structure and temporal patterning of the observed responses were similar to behaviour observed in heterosexual copulation. Furthermore, the res- ponses measured during the male-male encount- ers (pecks and head grabs; see Table I) fell to zero frequency in castrated males within 4 days after surgery and could be reinstated in approxi- mately the same period of time by daily injec- tions of testosterone cyclopentylpropionate. Sachs (1966) also reported on the similarity of male-male and male-female interactions, and he suggested that certain portions of the male's behavioural repertoire might be used to serve both sexual and aggressive functions. The present investigation had four primary objectives: (a) to compile a list of the behavioural units that are observed in male-male and male- *Present address: The Primate Research Centre, Beth- lem Royal Hospital, Monks Orchard Road, Beekenham, Kent, England. tPresent address: Battelle Seattle Research Center, 4000 NE 41st Street, Seattle, Washington 98105, U.S.A. (Requests for reprints should be sent to this address,) female social interactions; (b) quantitatively to compare and contrast the behavioural sequences observed in male-male and male-female inter- actions; (c) to replicate the earlier observations on the behavioural effects of castration and hor- mone replacement, and (d) to relate these be- havioural effects to changes in the size of the male's cloacal gland. As Sachs (1967) has ob- served, the easily-measured size of this gland appears to be a sensitive indicator of androgenic activity. The first pre-experimental phase of the investi- gation included a cinematographic analysis of male-male and male-female interactions. From direct observation, and repeated viewings of the fihns, a list was compiled of twenty-two reason- able discrete items of behaviour (Wilson 1967), which was similar to the list presented by Farris (1964). Table I includes the thirteen items relev- ant to the current experiment. Methods Subjects All the birds used in the experiment were obtained from three hatches of the 908 strain maintained by the Department of Poultry Hus- bandry, University of California, Davis. The birds were 15, 19 or 25 weeks of age when the experiment began. From hatching through age 5 weeks the birds were housed in a brooder; from that time until 2 weeks before the experi- ment they lived either in group (76 • 76 • 31 cm) or individual (28 • 18 x 20cm) cages; thereafter each animal was caged individually. A t4-hr on, 10-hr off, light cycle was maintained. Before and during the course of the experiment, 252