Scientists have identified two new species of mouse lemur, the saucer-eyed, teacup-sized primates native to rainforests in the African island of Madagascar. This brings the number of recognized mouse lemur species to 20, making them the most diverse group of lemurs known. They are shy and nocturnal making it very difficult to tell them apart with genetic sequencing.
The new mouse lemurs weigh 2.5 to 3 ounces (about 65 to 85 grams) and have grey-brown fur. “You can’t really tell them apart just looking at them through binoculars in the rainforest,” said senior researcher and study author Dr. Kappeler.
The researchers named one of the new species the Anosy mouse lemur, or Microcebus tanosi. Anosy mouse lemurs are close neighbors with grey mouse lemurs and grey-brown mouse lemurs, but genetic data indicates zero interbreeding. The other new species has been called the Marohita mouse lemur, or Microcebus marohita, after the rainforest where it was found. Unfortunately, this rainforest is threatened by ongoing habitat destruction.
During a 2012 return trip to the forest where the Marohita mouse lemur lives, it was evident that much of the lemur’s forest home had been cleared since the first visit in 2003. The state of the lemur’s habitat prompted the International Union for the Conservation of Nature (IUCN) to classify the new species as “endangered” even before it was formally described.
Mouse lemurs have lived in Madagascar for over 7 million years, but since humans arrived on the island around 2,500 years ago, logging plus slash and burn agriculture have gradually eroded the forest along with associated flora and fauna leaving only 10 percent of Madagascar’s original forests still standing today. In turn, the IUCN claim that lemurs are the most endangered mammals in the world.
A better understanding of mouse lemur diversity could help humans too since lemurs are relatively close to humans in the evolutionary family and in terms of a genetic match. They are certainly much closer than rates or mice our most common lab animals. One species even develops a neurological disease that is strikingly similar to human Alzheimer’s. With all this in mind, scientists consider these creatures important models for understanding the aging brain.