Mammals
Lemur
Lemuroidea · also called lemurs
A lemur is a primate that evolved in isolation. Its ancestors washed up on Madagascar tens of millions of years ago, found an island with no monkeys and few predators, and split into a whole radiation of animals: mouse-sized night hunters, leaping leaf-eaters, a woodpecker-like grub specialist, and the dog-sized singing indri. Nearly all of them are now sliding toward extinction as Madagascar’s forests burn.
Overview
Lemurs are the primate group Lemuroidea, found wild only on Madagascar and a couple of neighbouring islands. There are more than 100 species, from the 30-gram mouse lemur — the world’s smallest primate — to the 9-kilogram indri. They are strepsirrhine primates, an older branch of the tree than monkeys and apes, keeping a wet nose, sharp night vision, and a comb-shaped set of lower teeth used for grooming.
Island evolution
Lemurs reached Madagascar around 50 to 60 million years ago, almost certainly by rafting on floating vegetation, and diversified with no apes or monkeys to compete with. In most species the females are dominant over males — rare in mammals — probably an adaptation to the island’s unreliable climate. They communicate heavily by scent, and male ring-tailed lemurs settle disputes with a “stink fight”, wafting a scent-charged tail at a rival.
A group in crisis
About 98% of lemur species are threatened with extinction — the worst record of any large group of mammals. Madagascar’s forests have been widely cleared and burned for farmland, charcoal, and mining, and lemurs are also hunted for meat and taken as pets. Giant lemurs the size of a gorilla still lived on the island a thousand years ago; all were lost after people arrived.
Status
Endangered as a group and declining. Conservation rests on protected forest, community forest management, reforestation, ecotourism, and overseas breeding programmes for the rarest species, some of which number only a few hundred animals.
Lemur: common questions
Are lemurs monkeys?
No. Lemurs are primates but not monkeys. They belong to a separate, older branch of the primate tree, the strepsirrhines or wet-nosed primates, along with the bushbabies and lorises of Africa and Asia, whereas monkeys, apes, and humans are haplorhines. Lemurs kept features that monkeys have largely lost, such as a moist nose linked to a strong sense of smell, a reflective layer in the eye for night vision, a grooming claw on one toe, and a toothcomb. Their lineage split from the monkey and ape line more than 60 million years ago, so a lemur is roughly as distantly related to a monkey as a monkey is to a human.
Why are lemurs found only on Madagascar?
Madagascar separated from Africa long before lemurs existed, so the ancestral lemurs had to cross open ocean to reach it, most likely a small group or a few pregnant females rafting on a mat of vegetation washed out of an African river around 50 to 60 million years ago. Once ashore they found an island with no monkeys, apes, or large predators, and over millions of years their descendants evolved into every role those animals fill elsewhere, from tiny night-active insect hunters to large day-active leaf-eaters. Monkeys never made the same crossing, and on mainland Africa the early lemur relatives died out, out-competed by monkeys, leaving Madagascar as the last stronghold.
What are the largest and smallest lemurs?
The largest living lemur is the indri, a tailless black-and-white leaf-eater of the eastern rainforest that stands about 70 centimetres tall, weighs 6 to 9 kilograms, and sings loud, wailing family duets that carry for more than a kilometre. The smallest is Madame Berthe's mouse lemur, which weighs around 30 grams, small enough to sit in a tablespoon, and is the smallest primate in the world. Until about a thousand years ago Madagascar also had giant lemurs, including one, Archaeoindris, that may have weighed 160 kilograms, as big as a male gorilla. All of the giant forms were wiped out after people settled the island.
Do lemurs make good pets?
No, and keeping them is illegal in most places and within Madagascar. Lemurs are wild primates that can bite hard, scent-mark constantly with strong-smelling secretions and urine, and need to leap and climb over long distances, so they do poorly in a house. The pet trade within Madagascar, which takes infants from the wild after killing the mother, is also a direct threat to species that are already endangered. In their forests lemurs are not dangerous to people, though ring-tailed lemurs and a few others will raid crops and rubbish where forest meets farmland.