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BONNET MACAQUE

IDENTIFICATION: A grayish brown monkey with a circular “cap” of hair on the head, a prominent wrinkled brow and forehead, and a long tail (over 2 feet in males). DISTRIBUTION: Southern India. HABITAT: Forests, scrub, open areas. STUDY AREAS: Near Somanathapur Sandal Reserve and Byrankuppe (Mysore State), Dharwar, Karnataka (Tamil Nadu), and Lal Bagh (Bangalore), India; California Primate Research Center; State University of New York; subspecies M.r. diluta.

CRAB-EATING MACAQUE

IDENTIFICATION: A gray-green to reddish brown monkey with a slight pointed crest, pinkish face, and long tail. DISTRIBUTION: Southeast Asia including Indonesia, Philippines, Nicobar Islands, and introduced to Palau. HABITAT: Forests, swamps. STUDY AREAS: Angaur Island, Palau, Micronesia; Yerkes Regional Primate Research Center; University of California—Berkeley.

Social Organization

Both Bonnet and Crab-eating Macaques live in fairly large matriarchal groups containing numerous adult males and females as well as youngsters; males typically emigrate from their home group on becoming adults. Bonnet groups can be as large as 50–60 monkeys, but most average around 18–20 individuals, with four or five each of adult males and females. Male Bonnets demonstrate a strong tendency to interact and cooperate with one another, often forming supportive COALITIONS together. Crab-eating Macaques live in troops containing 40–50 individuals on average; smaller groups each contain 2–9 adult males. Large subgroups of youngsters, as well as some peripheral or solitary animals, also occur.

Description

Behavioral Expression: Male Bonnet Macaques frequently mount one another, using the same front-to-back position found in heterosexual copulation. A male may have anywhere from two to five different partners that he mounts; each male also varies in the proportion of times he mounts or is mounted. One male acted as the mountee in only 9 percent of his homosexual mountings, another did so in all of his mountings, though the average is a roughly equal proportion of mounter-mountee behavior, and reciprocal mounting occurs as well. In addition, male Bonnets engage in a wide variety of other same-sex behaviors, both affectionate and sexual, often within a coalition “bond” between them. Masturbation of another male is common in all age groups, especially younger males—one male holds or fondles the other’s penis and may even eat the semen from the resulting ejaculation (mutual masturbation also occurs). Males also sometimes grip and gently tug on each other’s scrotum; often, this is accompanied by embracing, nuzzling, grasping of the rump, tongue- clicking, and mouthing of the other’s neck or shoulders, all combined into a sort of ritualized “greeting” interaction. Another behavior, unique to homosexual interactions, involves two males rhythmically rubbing their rumps and genital areas together, often reaching back between their legs to fondle each other’s genitals. This behavior also occurs between females, as does mounting.

Homosexual mounting also occurs in male Crab-eating Macaques. In addition, male Crab-eaters may mouth and fondle the genitals and anal region of another male, including using their index finger to investigate the area. Males can also develop intense sexual friendships with one another, especially between older and younger males. In one such pair observed in captivity, affectionate embraces frequently led to sexual arousal and homosexual mounting, often accompanied by excited lip-smacking or crooning sounds; the male being mounted sometimes even turned his head to kiss his partner during a mount. Both consensual and nonconsensual mounting occurs in Crab- eating Macaques—in the former (54 percent of mounts between males), the mounted animal fully cooperates by standing still and helps support the weight of the other male (and perhaps even initiates the encounter). In nonconsensual mounts (46 percent of mounts between males), the mounting animal may corner his partner and hold him down (this also occurs in heterosexual mounting). Male Crab-eaters also occasionally engage in homosexual contact with other species. Wild Crab-eating Macaques sometimes allow male Orang-utans to perform fellatio on them, while in captivity they have been known to attempt copulation with males of a number of nonprimate species, including foxes.

An older male Bonnet Macaque in India mounting a younger male

Frequency: Homosexual mounting is very common in male Bonnet Macaques. In some populations, same-sex mounts exceed the number of heterosexual mounts by as much as four to one, and mounting between males can comprise 31 percent to 79 percent of all mounting. Sexual and affectionate behaviors between males occur in about a quarter of their interactions with one another. Female homosexual activity is somewhat less common: one study found that mounting between females occurred at rates that were two to seven times less than male-female or male-male mounting, although the rates of mutual rump rubbing with genital stimulation between females were only slightly less than between males. In Crab-eating Macaques, homosexual mounting accounts for 17–30 percent of mountings, and 10 percent of all interactions between males involve mounting (compared to nearly 50 percent of all interactions between males and females).

Orientation: Nearly all male Bonnet Macaques participate in