Animals Wildlife 10 Weirdly Wonderful Lemur Species These charismatic primates are incredibly diverse — and disappearing. By Jaymi Heimbuch Writer California Polytechnic State University, San Luis Obispo Jaymi Heimbuch is a writer and photographer specializing in wildlife conservation. She is the author of The Ethiopian Wolf: Hope at the Edge of Extinction. our editorial process Twitter Twitter Jaymi Heimbuch Updated January 05, 2021 25ehaag6 / Getty Images Share Twitter Pinterest Email Animals Wildlife Pets Animal Rights Endangered Species Lemurs' ancestors arrived in Madagascar during the Eocene Epoch, possibly by rafting over from Africa on mats of vegetation. The lineage has diversified widely in the 50 million years since, evolving into roughly 100 species, each unique in both behavior and appearance. Like many native Malagasy species, though, habitat loss has caused lemur populations to plummet. Nearly all lemur species now have a threatened status on the International Union for Conservation of Nature (IUCN) Red List, making this primate the most endangered mammal on Earth. Here are 10 unusual and beautiful lemurs that are in trouble. 1 of 10 Brown Mouse Lemur Artush / Getty Images The brown mouse lemur (Microcebus rufus) is among the shortest-lived of all primates, with a lifespan of only about 6 to 8 years in the wild and 10 to 15 years in captivity. It looks quite different from many other lemur species, too, with its reddish-brown dorsal and white ventral coloring (similar to a mouse's, hence the name). The nocturnal mammals inhabit the rainforests of eastern Madagascar, where they are vulnerable to extinction because of habitat loss due to slash-and-burn agriculture. 2 of 10 Common Brown Lemur Paul Souders / Getty Images The common brown lemur (Eulemur fulvus) lives in a wide variety of forest types, from lowlands to mountains, evergreen forests to deciduous forests. This range likely factors into its status as vulnerable, rather than endangered or critically endangered like so many of its lemur relatives. The species is mostly active during the day, but can be cathemeral, meaning it's active at varying times of the day and night depending on the season and availability of light. Its primary threat is habitat destruction, the result of a growing human population in Madagascar. 3 of 10 Aye-Aye 25ehaag6 / Getty Images Scientists debated whether the aye-aye (Daubentonia madagascariensis) was even a lemur until 2008. Before then, it was mistakenly classified under the order Rodentia, with beavers, house mice, and squirrels. It's famous for its slightly unsettling appearance — long fingers, yellowish irises, naked ears, and rodent-like teeth — but also for its tendency to hunt by echolocation (meaning it taps its long fingers on branches to hear whether there's grub in the bark). It's also the world's largest nocturnal primate species, now endangered due to habitat loss and trapping. These animals are often killed by the locals because of their spooky appearance. 4 of 10 Fork-Marked Lemur Gunter Lenz / Getty Images Similar in appearance to sugar gliders, fork-marked lemurs (Phaner) are named for the two dark stripes on their faces and heads. Found in patches of forest in north, west, and east Madagascar, they are among the least studied lemurs. It is known, however, that they get around by running along lower branches, about 10 feet (3 meters) off the ground. They can clear as much as 15 feet (4.6 meters) when jumping between trees and more than 30 feet (9 meters) when leaping to lower branches. All four species of the fork-marked lemur are endangered due to habitat loss. 5 of 10 Diademed Sifaka Yann Guichaoua-Photos / Getty Images The diademed sifaka (Propithecus diadema) hails from a type of lemur, belonging to the genus Propithecus, named for its unique "shi-fak" alarm call. The "diademed" in its name comes from the long, white fur that characteristically encircles its face. It lives most of its life in the forest canopy of eastern Madagascar, rarely coming to the ground. The tree dwellers can travel at 18 mph (29 kph) through the canopy using their strong legs, ideal for aerial propelling. The diademed sifaka is critically endangered due to habitat destruction and the fact that it is sometimes hunted by humans for food. 6 of 10 Mongoose Lemur Ava-Leigh / Getty Images The mongoose lemur (Eulemur mongoz) is one of only two lemurs found outside of Madagascar, as it has been introduced on the Comoros Islands. Even with greater distribution, it's still limited to a tiny area of Madagascar and therefore listed as a critically endangered species. Mongoose lemurs, like common brown lemurs, are cathemeral. The two sometimes even share territory. Coordinating their times of activity helps them avoid conflict and peaceably divvy up the resources of their forest homes. The exact number of mongoose lemurs left in the wild is unknown, but there are only about 100 in captivity. 7 of 10 Bamboo Lemur mlharing / Getty Images Prior to the 1980s, bamboo lemurs (Prolemur simus) were known as gentle lemurs (even though they're notoriously aggressive in captivity). Today, they share a name with their favorite food and are divided into five species and three subspecies — all found, of course, in bamboo forests. However, not all bamboo lemurs are alike. For instance, the Lac Alaotra (Hapalemur alaotrensis) variety lives in reed beds rather than forest canopy, and swims much more capably than most others. Bamboo lemurs are listed as critically endangered and are thought to have the smallest population size of any other lemur in Madagascar. 8 of 10 Blue-Eyed Black Lemur Ger Bosma / Getty Images The blue-eyed black lemur (Eulemur flavifrons) is somewhat of a misnomer considering only the males are black. Females tend to be reddish-brown in color. In any case, both sexes have striking blue eyes, which is rare among nonhuman primates. This species can be quite aggressive, known for having skirmishes within their troop and even committing infanticide against other species when in captivity. Deforestation has driven the blue-eyed black lemur to near extinction. The critically endangered mammal is now one of the 25 most endangered primate species in the world. 9 of 10 Golden-Crowned Sifaka Kevin Schafer / Getty Images The golden-crowned sifaka (Propithecus tattersalli) is known for its all-white or cream-colored coat topped with a crown of gold. These animals live in groups of five or six individuals, and females are the leaders. The only known predator is the fossa, but humans are an increasing threat, as poaching is common and slash-and-burn agriculture, commercial logging, charcoal production, and fires are rampant. As a result, the golden-crowned sifaka is critically endangered. Only an estimated 4,000 to 5,000 individuals exist in the wild, living in 44 fragmented pieces of forest. 10 of 10 Silky Sifaka Kevin Schafer / Getty Images The long, white fur and hairless face and ears of the silky sifaka (Propithecus candidus) is what sets it apart. The males use a scent glad on their chests to mark their territory, which results in an orange-colored patch — the only easy way to distinguish between sexes. Silky sifakas eat dirt in addition to leaves and seeds. They get nutrients from consuming clay and soil, a behavior known as geophagy. The silky sifaka is one of the 25 most endangered primates due to hunting and deforestation. Only about 250 mature individuals are left, according to the IUCN.