Male assessment of female choice in hamadryas baboons

Summary

• 1 The study investigates the conditions under which a hamadryas male \lsrival\rs respects a pair consisting of a male \lsowner\rs and his female rather than fighting the owner and attempting to appropriate the female. Two types of laboratory experiments were carried out on a colony of six males and six females: (a) choice tests that yielded a score of preference of each female for each male and of each male for each female, and (b) tests that measured the tendency of the rival to respect a pair in a given triad.

  The following results were obtained: (1) The respect of the rival was not correlated with the preference of the owner or of the rival for the particular female. (2) The respect of middle- and low-ranking rivals was positively correlated with the preference of the female for the owner. The two males highest in rank did not adhere to this strategy.

• 2 These results are functionally interpreted in terms of an asymmetric \lspayoff\rs of the female to the males. Under a given dominance relationship (or asymmetry of resource holding potential) between the two males, a female with a strong preference for her present owner is too costly a prize for the rival in terms of herding effort and the risk of losing her again. However, if a rival is informed that the female will not choose her present owner, his attack may temporarily free her from the owner's herding and permit her to exert her choice in favor of the rival. The strategy seems particularly adaptive in males that cannot play out their superior rank. The causal interpretation is that baboons may be capable of assessing aspects of a relationship among two other members of their group.