Nasalis

Nasalis is a genus of Old World monkey, specifically a type of proboscis monkey. The genus contains only one species, the proboscis monkey (Nasalis larvatus), which is native to the islands of Borneo and Sumatra in Southeast Asia.

Description

The proboscis monkey is a large species, with males reaching up to 75 cm (30 in) in length, not including the tail, which can add an additional 75 cm. Females are slightly smaller, typically measuring around 60 cm (24 in) in length. The most distinctive feature of the proboscis monkey is the large, pendulous nose of the males, which can reach up to 10 cm (4 in) in length. This nose is thought to be a result of sexual selection, with larger-nosed males being more attractive to females.

Habitat and Distribution

Proboscis monkeys are found in a variety of habitats across Borneo and Sumatra, including mangrove forests, swamp forests, and lowland rainforests. They are particularly associated with rivers and coastal areas, and are excellent swimmers.

Behavior and Diet

Proboscis monkeys are diurnal, meaning they are active during the day. They live in groups of up to 30 individuals, with a single dominant male and multiple females. Their diet consists primarily of leaves, fruits, and seeds, although they will also eat insects and other small animals.

Conservation Status

The proboscis monkey is currently listed as Endangered by the International Union for Conservation of Nature (IUCN), due to habitat loss and hunting. Conservation efforts are focused on protecting the monkey's habitat and reducing hunting pressure.

See Also

• Old World monkey
• Borneo
• Sumatra
• Endangered species