Formosan rock macaque Formosan rock macaque The Formosan rock macaque ("Macaca cyclopis"), Formosan rock monkey, or Taiwanese macaque, is a macaque endemic to the island of Taiwan and has been introduced to Japan. Besides humans, Formosan rock macaques are the only native primates living in Taiwan. Rock macaques measure 50–60 cm and weigh 5–12 kg, generally females are smaller. Their tails are moderately long and measure 26–45 cm. This macaque is brown or gray in color. Like all other macaques, it has specialized pouch-like cheeks, allowing it to temporarily hoard its food. The gathered morsels are eaten sometime later, in safe surroundings. Among
Barbary macaque he should mate. This is further supported by the fact that male ejaculation peaks at the same time that female sexual swelling peaks. There is not a sufficient change in female sexual behaviour around the time of ovulation in order to demonstrate to the male that the female is fertile. The swellings, therefore, appear necessary for predicting fertility. Barbary macaque females differ from other non-human primates in that they often mate with a majority of the males in their social group. While females are active in choosing sexual associations, the mating behaviour of macaque social groups is not entirely determined