A small lemur on a small island (Image: Louise Jasper)

It’s a lemur lover’s dream: cute and totally unafraid. A new population of dwarf lemurs has been identified on a small, uninhabited island off the north coast of Madagascar.

The group could be a new species, and are unafraid of humans, suggesting they may have been isolated on their rocky home for a long time.


“I’m sure we could have touched them if we had tried,” says Charlie Gardner a conservation researcher at the University of Kent, UK. “They didn’t approach us, but they didn’t flee either – they just sat there transfixed on their branches.”

Gardner and his wife Louise Jasper, a photographer, discovered the lemurs while holidaying on the island, called Nosy Hara, in April.

At only 312 hectares, the island is smaller than Central Park in New York, and largely covered in craggy limestone rock. There are small patches of forest in the valleys, which is where they came across the lemurs while going for a stroll after dark.

“We always go for night walks in any forest we visit, because lots of species of reptile and amphibian only emerge at night,” says Gardner. “We weren’t looking for lemurs, and certainly didn’t expect to see any there, because the island seems too small to support a population of them.”

But as they looked for chameleons and snakes, they suddenly saw their torchlight reflected back at them by lemur eyes.

They immediately recognised the small grey animal as a type of dwarf lemur (Cheirogaleus), but were surprised – these have never been seen off Madagascar’s main island.

The nearest other dwarf lemur species lives 25 kilometres south-east of Nosy Hara, and is red and much bigger. The nearest small grey lemurs are about 64 kilometres away.

They spotted another individual not long after, and four more the following night. “They seemed quite small for dwarf lemurs and were incredibly tame, which made us wonder if they are a restricted to this island because both dwarfism and predator naiveté are characteristics of island species,” says Gardner.

Small and fearless

Dwarfism is a common evolutionary adaptation in animals that become isolated on islands and have to adapt to a smaller ecosystem. Apparent tameness can be a sign that a species has been on an island for a long time, as fear of predators is a crucial survival trait unless the environment is very safe, and takes a while to be lost by evolution.

There are no mammal predators on Nosy Hara, and the types of bird that would normally scare a lemur do not live there either. There are several threatening snake species, and Gardner suspects the lemurs will be fearful of those at least.

But is this a new species?

“The evidence is very preliminary,” says Peter Kappeler of the German Primate Centre in Goettingen.

We can’t know for now, since no tissue or measurements were taken. It is also possible that the animals seen were small because they were juveniles, Kappeler says.

However, the circumstantial evidence is suggestive, he says. “Given the lack of fear on this predator-free island, it is plausible that these animals have lived there for long enough to exhibit insular dwarfism and reproductive isolation from their ancestors.”

Name that lemur

Based on the size of the island and the usual population density of other lemur species, Gardner estimates that the number of lemurs is likely to be in the hundreds at most.

Gardner and Jasper hope that other researchers will now visit the island and confirm whether the lemurs are a new species.

“Finding a new species is only the start of a very long process before it can be scientifically described, which often requires years of lab work,” says Gardner. “Unfortunately I don’t have the training or a lab to carry out the analyses required.”

Because of this, Gardner will not be able to name the lemurs, should they be confirmed as a new species. But he says that, if he did have the chance, he would name them Cheriogaleus nosiharaensis, after the island, which also happens to be home to one of the world’s smallest reptiles, the Brookesia micra chameleon.

Journal reference: Primates, DOI: 10.1007/s10329-015-0479-x