Data analysis navigates lookalikes to try to pin down the true number of mouse lemur species

In some parts of the world, animals are going extinct before scientists can even name them. Such may be the case for mouse lemurs, the saucer-eyed, teacup-sized primates native to the African island of Madagascar. There, deforestation has prompted the International Union for the Conservation of Nature (IUCN) to classify some of these tree-dwelling cousins as “endangered” even before they are formally described.

Duke professor Anne Yoder has been trying to take stock of how many mouse lemur species are alive today before they blink out of existence. The findings are published in the journal Nature Ecology & Evolution.

It’s not an easy task. Mouse lemurs are shy, they only come out at night, and they live in hard-to-reach places in remote forests. To add to the difficulty, many species of mouse lemurs are essentially lookalikes. It’s impossible to tell them apart just by peering at them through binoculars.

When Yoder first started studying mouse lemurs some 25 years ago, there were only three distinct species recognized by scientists. Over time and with advances in DNA sequencing, researchers began to wonder if what looked like three species might actually be upwards of two dozen.

In a new study, Yoder and dozens of colleagues from Europe, Madagascar and North America compiled and analyzed 50 years of hard-won data on the physical, behavioral and genetic differences among mouse lemurs to try to pin down the true number.

While many mouse lemur species look alike, they have different diets, and males use different calls to find and woo their mates, the researchers explain. By pinning down their number and location, researchers hope to make more informed decisions about how best to help keep these species from the brink.