Lutungs shine with their coloured coats
Becky Crew is a Sydney-based science communicator with a love for weird and wonderful animals. From strange behaviours and special adaptations to newly discovered species and the researchers who find them, her topics celebrate how alien yet relatable so many of the creatures that live amongst us can be.
LOOK AT THIS beautiful family. Named the ebony lutung (Trachypithecus auratus), these Indonesian natives belong to one of the most unique group of primates in the world, the lutungs.
Lutungs spend their days in the forests of Southeast Asia, including the Indonesian islands, Peninsular Malaysia, Sumatra, Borneo and India, keeping to the coast and flanking the rivers where the trees offer the newest, most nutritious fruits and leaves.
As with all primates, their social lives are everything, and the males in particular have it pretty good within their family groups. It’s often just one of them with a bunch of females, and sometimes there’ll be as many as 40 females in a single harem. Not that the females mind too much – they groom each other and cuddle up in the trees and help each other with their young.
There’s usually very little aggression within a family group, possibly because lutungs specialise in eating leaves, so there’s always plenty of food to go around. It also helps that these monkeys feed while facing the tree trunks – if you don’t know what your competition is eating, you can’t get jealous!
The females will each have one infant per pregnancy, and these babies are born looking like furry little nuggets of gold.
In ebony lutungs, the infants are born golden before quickly developing the dark coat and skin of its parents, while in silvered leaf monkeys (Trachypithecus cristatus), the infant will retain its orange coat for up to five months.
In the subspecies Trachypithecus auratus auratus from East Java, some individuals will retain their orange coat throughout adulthood.
This special orange coat is called a natal coat, and researchers have suggested that its purpose is to make sure the dominant males don’t kill their young sons before they have a chance to mature and form separate family groups of their own.
It could also help families to quickly locate their infants in a moment of danger, like when a rival group infiltrates their territory. Either way, it’s one of the most stunning colours you could hope to see in a primate.