Abstract1. During 15 months' observation of a troop of free-ranging baboons, 13 of 16 female sexual cycles included a period of sexual consortship. Sexual consortships were defined in terms of both frequent proximity and exclusive sexual interaction between partners. 2. Female preference, male preference, and female rank were all important in determining the frequency with which specific individuals formed sexual consortships. The Alpha male was preferred by 7 of the 8 adult females, and, as a result, was involved in 10 of the 13 sexual consortships. The subordinate male formed sexual consortships twice when 2 females were swollen simultaneously and once when a female preferred him over the Alpha male. In the former two cases the higher-ranking female consorted with the Alpha male and the lower-ranking female with the subordinate male. In the latter case the Alpha male did not interfere with the subordinate male's sexual consortship. As an indication of male preference, on one occasion both the Alpha and the subordinate male ignored the presents of a fully swollen female, even though she was the only sexually receptive female in the troop at the time. 3. Sexual consortships were formed from 1 to 14 days after the female had become fully swollen, and invariably ended at least one full day before the onset of deturgescence. Sexual consortships ranged in length from 1 to 8 days, with a mean length of 3.5 days. "Successful" sexual consortships (i.e. those which resulted in conception) were more likely than others to be in progress on cycle days D-7, D-6, and D-5. 4. In the days preceding sexual consortship, females were more important than males for both the maintenance of proximity and the initiation of mounts. In contrast, during sexual consortship males were more important for the maintenance of proximity, while females were relatively less responsible for the initiation of mounts. 5. During sexual consortship partners maintained a generally higher rate of mounts with insertion that at other times, and their mounts with insertion were more "clumped" in time. There was no indication, however, of any peak in sexual activity relative to a particular day before the onset of deturgescence. 6. The formation of a sexual consortship did not appear to interrupt a female's social interactions with other animals in the troop. In most cases, however, proximity between females and their offspring increased during the period immediately after consortship had ended. 7. Although rates of female-female aggression were not affected by the formation of sexual consortship, adult females were more likely both to ignore threats from higher-ranking individuals and to be supported by adult males during sexual consortship than at other times.
Play and social behaviour of calves with or without access to their dam and other cows
