Lemurs of Madagascar: Surviving on an Island of Change
Lemurs in Madagascar: Now
The ring-tailed lemurs that romp around the research camp at the Beza Mahafaly Special Reserve in southwest Madagascar spend plenty of time behaving badly. They slide down tents, peer at their reflections in pickup truck windshields, and rummage through trash cans. It's their playful and versatile nature, in part: as "generalist" species, ring-tails can adapt to a range of habitats. But this population also resides in a conservation area with abundant resources and few threats. "The lemur group at the camp has a lot of luxury in terms of time," says Michelle Sauther, an anthropologist from the University of Colorado at Boulder who spends three months of the year at Beza Mahafaly. "If they don't have to run around looking for food all the time, even ring-tailed lemurs can sit back and relax."
A ring-tailed lemur at Beza Mahafaly Special Reserve checks itself out.
Local villagers offered to set aside 600 hectares of the Beza Mahafaly forest to form the reserve in the late 1970's. Remote and nearly the smallest protected area of the 46 on the island, it is hardly as popular with eco-tourists as the rain forests of Ranomafana and Perinet. But the range of Malagasy habitats it contains is remarkable. These include a lush "gallery" forest that lines the seasonal Sakamena River and a dusty "spiny desert" forest with towering cactuslike trees. Beza's habitats support five of the dozens of lemur species on Madagascar, most notably the housecat-sized, raccoon-faced ring-tails and the paler, silkier Verreaux's sifaka.
Sauther has monitored lemurs at Beza Mahafaly for about twenty years. With conservation as its goal, her work aims to understand how changes to Madagascar's environment—mostly brought about by human beings—affect the behavior, health, and evolution of lemurs. In the land outside the reserves, these changes have not afforded lemurs much time to goof off.
First Encounters
Madagascar was one of the last landmasses settled by humans. It is likely that maritime traders sailing the Indian Ocean first stepped on its southwest coast some 2,300 years ago. The earliest indirect evidence of the "human footprint" is the slashed bones of extinct lemurs found at Taolambiby, a dusty creek bed seven kilometers or so from Beza Mahafaly. Hundreds of hacked bones of Verreaux's sifaka were also dug up at Taolambiby. The cut marks, probably exacted by iron butchering tools, are an eerie testament to some of humans' first impacts on lemurs.
Scientists keep tabs on individual Verreaux's sifaka at Beza Mahafaly Special Reserve with tags and collars.
The locals near Beza Mahafaly no longer eat sifakas (it's taboo), but lemurs are still hunted elsewhere in rural Madagascar. More deleterious than hunting pressure, however, has been the swift, dramatic effects of agriculture. Much of Madagascar's original forest has been converted to cropland, pastureland, or eroded wasteland via axe, machete, and fire. (Besides reducing habitat for arboreal species like lemurs, slash-and-burn deforestation exacerbates soil erosion, which occurs at a higher rate in parts of Madagascar than anywhere else in the world.) These days, deforestation occurs at a rate of just under 1 percent a year. Although there are only 32 humans per square kilometer on Madagascar, the island's population is poised to double by the year 2025. At least 16 species of lemurs have disappeared since humans arrived, and all lemurs living today are threatened with extinction to some degree.
