Distribution and Habitat
Lemurs survive only on the island of Madagascar off the southeast coast of Africa in the Indian Ocean (shown in green), and on the neighboring Comoros islands. The various species of lemurs can be found in habitats as different as the lush, wet, rainforest of eastern Madagascar and the very dry spiny desert in the southwest.
Coquerel's sifaka Lemurs are primates. The species living today are small to medium-size mammals ranging from the smallest of all primates, the tiny pygmy mouse lemur (Microcebus myoxinus), which weighs only 30 grams (1 ounce), to the largest lemurs, the indri (Indri indri) and the diademed sifaka (Propithecus diadema diadema), which weigh slightly over 7 kg (15 pounds) and can reach 4 feet (1.2 m) tall.
Lemurs like all, primates have binocular vision and grasping hands. However, unlike most other primates, lemurs and other prosimians have a rhinarium, a moist, very sensitive nose.
With the exception of the indri, lemurs have long furry tails. They use these tails for balance when leaping through the forest canopy, but unlike some New World monkeys, these tails are not prehensile, and lemurs cannot hang from them.
The Evolution of Lemurs
How and when lemurs diverged from the lineage that led to monkeys is unclear. Although it was once thought that lemurs were on Madagascar when the island separated from Africa, recent advances in geological science have shown that Madagascar was separated from Africa by hundreds of kilometers before lemurs evolved. Accordingly, the ancestors of Madagascar's lemurs must have crossed over from Africa on floating vegetation early in primate evolution and become reproductively isolated from Africa.
Once on Madagascar, the lemurs underwent an amazing radiation, evolving into many different species. Then, about 2,000 years ago, the first human settlers arrived on Madagascar from the Malaysian-Indonesian area. By the time the Europeans who wrote about the natural history of the island reached Madagascar in the mid-1600s, 15 species of lemurs, forming eight entire genera, had become extinct.
All of these 15 fossil lemur species were larger than any of the surviving species. The largest of these was Archaeoindris, which is estimated to have weighed 350 to 440 pounds (160 to 200 kg), or as much as an adult male gorilla. Another group, the "sloth lemurs" including Babakotia and Paleopropithecus, weighed 44 and 88 pounds, (20 and 40 kg) respectively, and appear to have traveled by hanging upside down from branches like current South American sloths. Another unusual extinct lemur, Megaladapis, 88 to 175 pounds, (40 to 80 kg), appears to have hung onto trees much like an Australian koala. The loss forever of these bizarre and wonderful animals in the recent past is unfortunate. As you know these species will not be the last to disappear unless we all act quickly to preserve the remaining species.
Lemurs are much less closely related to humans than are monkeys and apes. Living lemurs more closely resemble primitive primates that lived millions or tens of millions of years ago than do living monkeys. For this reason, the study of living lemurs can provide unique and highly valuable insight into primate evolution, including the evolution of human ancestors.
There are now 88 species of living lemurs divided into five surviving families:
Cheirogaleidae—Mouse and dwarf lemurs. This family boasts the smallest of all primates, the gray or lesser mouse lemur. These lemurs are nocturnal. They are solitary foragers but sleep in small groups.
Lemuridae—True lemurs. Our animals on Lemur Island, the ring-tailed lemur and the red-fronted lemur are found in this family as well as the red-ruffed lemur in the Small Mammal House. These lemurs have long bushy tails used for balancing as they jump from branch to branch. They have a well-developed sense of smell and often scent mark their territories.
Megaladapidae—Sportive lemurs are nocturnal and arboreal. They are primarily leaf eaters.
Indriidae—Woolly lemurs and sifakas are the largest of the lemur families. Some can reach four feet (1.2 m) from head to toe. The sifakas have long spring-like legs that allow them to jump over 30 feet (9 m) from tree to tree.
Daubentoniidae—The only member of this family is the rare aye-aye. They are solitary and nocturnal. They have elongated, narrow, flexible fingers that they use to reach under tree bark for grubs.
Lemurs spend most of their time in trees or large bushes, although the ring-tailed lemur, the most terrestrial species, may spend as much as half of its day on the ground. The smaller species tend to be nocturnal and solitary, but most of the larger species are active during the day, or diurnal. The diurnal lemurs also tend to live in social groups or mobs.
Lemurs feed primarily on leaves and fruits, and most are arboreal. For some of the nocturnal lemurs, insects form a large part of their diet.
Lemurs communicate vocally as well as through scent markings.
Several species of lemur are endangered, largely due to deforestation. They are also hunted and trapped for the pet trade and food.