Green monkey

Distribution and history: The green monkey is native to West Africa from Senegal and The Gambia to the Volta River, with insular populations on the Bijagós Islands. Human-mediated introductions occurred: to the Cape Verde islands as early as the second half of the 16th century and to West Indian islands (Saint Kitts, Nevis, Saint Martin, Barbados) in the late 17th century via slave ships from West Africa. An introduced colony in Broward County, Florida derives from 20th-century zoo escapees.

The green monkey has golden-green fur with pale hands and feet. The tip of the tail, the backs of the thighs, and cheek whiskers are golden yellow. Unlike some congeners, it lacks a distinguishing band of fur on the brow. Males exhibit sexual dimorphism including a pale blue scrotum. Adult male body mass ranges roughly 3.9–8.0 kg with length about 420–600 mm; adult females 3.4–5.3 kg and 300–495 mm in length.

Behavioral/ecological traits: highly social, typically living in groups from about 7 up to 80 individuals with clear social hierarchies manifested through grooming and gender relationships. Communication is both vocal and non-verbal, including distinct alarm calls—some specific to particular predators—and facial and bodily signals. Diet is omnivorous and varied (fruits, invertebrates, shore foods such as crabs in coastal groups). Reproduction is seasonal (most populations breeding April–June; a local variant breeding October–November), polygynous with alpha males controlling mating, females maturing at about two years and males around five, and maternal care lasting roughly a year. Predators in West Africa include leopards, martial eagles, and pythons; in introduced Caribbean ranges humans are recorded as the primary predator; chimpanzees have been observed preying on them in at least one West African locality.