Lemurs of Madagascar: Surviving on an Island of Change

Lemurs in Madagascar: Then

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LEMURS OF BYGONE DAYS

The French East India Company appointed Étienne de Flacourt governor of Madagascar in the late 17th century. His 1661 tome Histoire de la Grand Isle Madagascar describes the animals he saw and was told about during his exploration of the country. It provides tantalizing details about native megafauna, or large animal species, that no longer exist today. One creature, called the tretretretre, was described as large as a two-year-old calf, having the "face of a man," long digits, curly hair, and a short tail. Residents were "very afraid of it and flee it as it does them." Paleontologist Laurie Godfrey believes this animal to be the extinct sloth lemur Palaeopropithecus.

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AMNH library rare book collection

“There is some evidence that there was a single colonizing ancestor of lemurs on Madagascar, long after the island was already separated from Africa and other bodies of land,” says Godfrey. She digs and studies lemurs’ “subfossil” bones—i.e. bones buried too recently to fossilize—to learn which species lived here when. DNA analysis of present-day lemurs suggests that lemurs’ original ancestor lived nearly 70 million years ago, a few million years before the dinosaurs disappeared. No one is certain if this “proto-lemur” negotiated the surrounding waters to arrive on the island or if primates (including lemurs) evolved on the once-connected landmasses from earlier inhabitants. Several theories exist about lemur origins, but molecular studies have repeatedly shown that this ancestor diversified into eight families of lemurs: three extinct and five still alive. Scientists call this evolutionary process “adaptive radiation.” “The idea suggests that high diversity results because animals adapted to different niches, different habitats, and different foods within the same habitat,” says Godfrey.

Coping with Change

Such an ancient adaptive radiation means that the lemurs of Madagascar—both extinct and living—are quite different from one another. Every extinct lemur was larger than the largest living today, the domino-colored, bushy-eared, tailless indri, which is the size of a 7-month-old child. The tiniest lemur, the mouse lemur, is closer in size to its namesake. Some lemurs eat leaves, others fungus, and still others the soil near termite mounds. Many lemurs have odd adaptations that give them a competitive edge, such as the aye-aye’s lengthy fingers, which it uses to pluck woodboring insect larvae. Another instance is the bamboo lemur’s resistance to the cyanide naturally present in its food, bamboo shoots. This allows it to exploit a resource others avoid.

Some scientists argue that lemurs may have evolved in the many ways they did to cope with limited resources on a constantly changing island environment. "Madagascar is a great place to study both natural and human-induced changes in the environment," says Godfrey. "It's a natural experiment, so to speak. We desperately need to understand its dynamics if we are going to conserve the remaining primates not only on Madagascar but also in the rest of the world."

To find out what lemur scientists have learned, read Lemurs in Madagascar: Now.