Patterns of mating among male patas monkeys (Erythrocebus patas) in Kenya

Abstract

An habituated group of wild patas monkeys was observed in Kenya for 550 h in 1984. Observations were made primarily during an interval that, as previous studies at the same site had demonstrated, coincided with the annual mating and conception periods. Earlier field studies of patas at other sites had reported that heterosexual patas groups had only a single resident adult male and that mating was harem-polygynous. At the Kenya site, by contrast, as many as six males were simultaneously resident and mated in the group during the conception period. Males adopted a variety of tactics to gain access to receptive females, ranging from opportunistic mating to attempts at sequestration that resembled consort behavior in other cercopithecoids such as savanna baboons and rhesus macaques. Aggressive competition for access to females took place among the males, although the number of completed copulations per male did not bear a positive relation to agonistic dominance rank. For patas monkeys, harem polygyny is only one available option within an overall mating system that is best described as a form of promiscuous polygyny, especially during periods when conception is most likely.

Sexual Selection, Seminal Coagulation and Copulatory Plug Formation in Primates

“…This difference is statistically significant (at the genus level: z = 4.19, n 1 = 16, n 2 = 11, p < 0.0001). Inclusion of the patas monkey (E. patas) among the polygynous forms might be questioned because, although these monkeys form one-male units [46], multimale influxes occur in some groups during annual mating seasons [47,48]. Likewise, the mating system of the orangutan (Pongo) is problematic, since females may, or may not, exhibit MP matings [33].…”

Myth of the typical primate

“…In fact, although most copulations occur within groups, many female primates also copulate, and may conceive, with extragroup males (ringtailed lemurs: Sussman, 1992;sifaka: Richard, 1985a; patas monkeys: Rowell and Chism, 1986;Harding and Olson, 1986; forest guenons: Rowell and Chism, 1986;[Vol. 37, 1994 Cords, 1987; Barbary macaques: Mehlman, 1986;Small, 1990; Japanese macaques: Sprague, 1992;muriquis: Strier, 1994).…”

“…Indeed, these differences have been used to justify distinctions between chimpanzees, as exceptional primates, and savanna baboons and other well-studied, female-bonded cercopithecines, as more "typical" primates. Yet, even among the ecologically similar semiterrestrial cercopithecines, such as baboons, vervet monkeys, patas monkeys, and macaque species, social relationships differ markedly (e.g., Cheney and Seyfarth, 1983;Harding and Olson, 1986; Rowel1 and Chism, 1986;de Waal and Luttrell, 1989). Similarly, there are significant differences in the societies of common chimpanzees and the closely related bonobos (Furuichi, 1989;Ihobe, 1992).…”

“…In fact, although most copulations occur within groups, many female primates also copulate, and may conceive, with extragroup males (ringtailed lemurs: Sussman, 1992; sifaka: Richard, 1985a; patas monkeys: Rowell and Chism, 1986;Harding and Olson, 1986; , 1992). The importance of sexual access to particular females within groups is more clear-cut, because while a male that does not belong to a heterosexual group may still have opportunities to fertilize females, a male that is unable to mate will not.…”

Indiscriminate Response to Infant Calls in Wild Patas Monkeys (Erythrocebus patas)

“…In Laikipia, as many as 6 males (out of 10 males in all) were simultaneously resident and mated with females in a harem [37], and 3 males were resident in another harem during a mating season [38]. At least 6 males (out of 16 males in all) were simultaneously resident and mated, and mating by the harem holder accounted for only 31% of matings in the KK group during a mating season in 1986 [35,39].…”