He obviously overlooked female macaques, who, unlike the males, apparently have quite a sex drive. As a result, they engage in torrid lesbian monkey lust, grinding themselves against other females, stimulating themselves with their tails, etc.
Hot lesbian monkey pr0n.
"They mount each other, often involving pelvic thrusting, and will gaze into each other's eyes," says Dr. Paul Vasey of the University of Lethbridge in Canada. Vasey also found evidence of strong same-sex bonds, and even evidence suggesting that some females engaged in lesbian sex to excite unwilling males... "Mutual sexual attraction was the impetus for the formation and maintenance of homosexual consortships," he contends.
Fuuuunky. Fuuuunky monkey. makes me think of that Morris Day and the Time song...
"My jungle love... Ooo-eee-ooo-eee-ooo!"