Madagascar is a veritable wonderland of unique species of plant and animal life. This includes the painfully adorable mouse lemurs, the world’s smallest primates. The very smallest, Madame Berthe’s mouse lemur, is on average no longer than 9.2 centimeters (3.6 inches) and weighs around 30 grams (1.1 ounces).

Now, a new paper in the journal Molecular Biology describes three new species hiding within the forests of Madagascar, meaning that there are at least 24 residing on the sizable island. As little as 20 years ago, only two mouse lemur species were known to science, but new genetic techniques have uncovered the identity of several others since then, including the latest members of the family.

“By using new, objective methods to assess genetic differences between individuals, we were able to find independent evidence that these three mouse lemurs represent new species,” Peter Kappeler, head of the behavioral ecology and sociobiology unit at the German Primate Center and a co-author of the study, said in a statement. “This new information is an important element towards better understanding how biodiversity on Madagascar arose.”

 

 

^{Mouse lemurs being handled at Duke Lemur Center, who also took part in this research. Duke Lemur Center via YouTube}

Mouse lemurs, whose Latin name means “ghost,” are nocturnal critters that feast on insects (and their secretions), gum, fruit, flowers, nectar, leaves, and buds. They’re decidedly cryptic: Despite the fact that they all look pretty much the same, with their brown fur and large eyes, research has shown that since first radiating from their last common ancestor 10 million years ago, they have developed into tens of different species, all with very different genetic compositions.

By rigorously assessing the DNA of 16 individual lemurs at two sites within the southeastern Tsinjoarivo forest – eight from the western section and eight from the eastern – the researchers confidently identified at least two previously undiscovered mouse lemur species.

Consequently, the genus Microcebus now includes M. manitatra and Ganzhorn’s mouse lemur (M. ganzhorni), the latter of which is named after a professor of ecology from Hamburg University who has been involved in researching and conserving lemurs for decades.

The third, M. boraha, was located on Île Sainte-Marie, a tiny isle off the eastern coast of the mainland. To the observer, however, they do all physically resemble each other, with almost no distinguishing features of any kind.

^{The grey mouse lemur, extremely closely related to the two newly discovered mainland species. David Thyberg/Shutterstock}

According to the International Union for the Conservation of Nature (IUCN), more than 100 species of lemur – the mouse lemur included – belong on its Red List, which means that they are threatened by extinction. In fact, lemurs hold the ignominious title of world’s most endangered group of mammals, thanks to prolific hunting and deforestation.

This new study highlights that there are even more lemur species out there waiting to be protected, although such efforts are hampered by their presence in one of the poorest countries in the world. Sadly, up to 90 percent of all lemur species face extinction within the next 25 years.