A slim, long-tailed monkey that looks as if it’s been dusted with mist. It has a small, fine-boned face, a soft crest of hair on top of the head, and a long, graceful tail that helps it balance high in the canopy. Its fur can range from dark grey to almost whitish, but a common look is a grey or “salt-and-pepper” back with pale underparts and a darker head and crest. Unlike chunky macaques, the surili has a narrow chest and long limbs but a big, rounded belly. That “pot-bellied” look isn’t fat – it comes from its special leaf-eating stomach, which is divided into sacs and full of friendly bacteria that help it break down tough plant fibres.

This monkey lives only on the island of Java in Indonesia, mostly in the western half and into parts of central Java, making it a true Javan local. It inhabits primary and secondary rainforests from low hills up into cooler mountain slopes, slipping through the mid and upper canopy rather than coming to the ground. Javan surilis are diurnal, active in the daytime, but they prefer the softer light of morning and late afternoon and spend a lot of time resting or grooming in between feeding bouts.

Their diet is strongly focused on young leaves, more so than many of their close relatives, though they also eat flowers, fruits and seeds when they are available. The leaves they choose are often tender, newly grown ones from particular tree species, so they move along regular feeding routes, returning to favourite trees as fresh foliage comes in. By swallowing and later dropping seeds from the fruits they do eat, they help replant their forest home, even though leaves are the main item on the menu.

Distribution

Country

Population est.

Status

Year

Comments

Indonesia

5,000–12,000

Official estimate

VU

2022

Jawa