Lemurs of Madagascar: Surviving on an Island of Change

Lemurs in Madagascar: Now

Generalists vs. Specialists

Lemur research in the protected areas helps inform conservation. At Beza Mahafaly, ring-tailed lemurs and sifakas are observed, counted, captured, DNA-sampled, checked for parasites, collared with radio-tracking tags, then released; they even have casts made of their teeth. Both populations at the reserve appear stable. "Ring-tailed lemurs are widespread in the south of the island, but that's not to say they're not threatened," says Sauther. "But they seem to be able to deal biologically with habitat change." The generalist ring-tails can cope with, and even take advantage of, some anthropogenic change. For one, they'll eat anything: flowers, insects, fruit, but also less-nutritious tourist handouts, crops, and food refuse. "They're able to exploit a wider resource base than the sifakas, who have a more narrow folivorous, or leaf-eating, diet," explains Sauther.

Ring-tails are also more terrestrial than the arboreal, "specialist" sifakas. "Ring-tailed lemurs are able to utilize all parts of the forest," says Sauther, "from the very tops of the trees to the ground itself." Biologically, sifakas can't afford the energy costs of frequent travel across a denuded habitat, so they leap on trees instead. But when the trees disappear, sifakas are stuck. "Many of the fossil lemurs, the extinct species, were hyperspecialized," says Sauther. "They simply could not adjust to the loss of habitat."

Many regions around Beza Mahafaly are largely treeless, instead dotted with cassava, maize, and sweet potatoes and with grazing zebu cattle and goats. Scientific comparisons of lemurs inside and outside the park show that the reserve animals generally travel less far to forage and are healthier. The rich resources of the reserve do appear to be a magnet for ring-tailed lemurs: the population density within the reserve is much greater than in the surrounding habitats. But higher animal densities in these isolated reserves bring new population pressures.

Many Populations, Same Island

"One of the things that I've noticed over the almost 20 years that I've worked here is that reserves really do work," says Sauther. "But they only work when you have the local people involved." Beza Mahafaly was among the first Madagascar conservation projects to involve local residents, a few thousand of whom live in straw-roofed huts outside the reserve. The villagers agreed to protect the lemur habitat, and governmental and nongovernmental organizations agreed to improve the residents' water access, roads, schools, and other infrastructure. "The villagers are participating in the long-term research that we've been undertaking at Beza Mahafaly," says Joelisoa Ratsirarson. He's Madagascar's general secretary of the minister of the environment, water and forestry and also a biologist who studies the park's sifakas. "We train the villagers to monitor the survivorship and movement of the lemurs. The local population is very helpful in protecting the reserve and really respects the lemurs."

Ratsirarson says that although the Malagasy government "lacks the means for conservation activities," habitat protection is a political priority. It is mostly accomplished in cooperation with international groups like the World Wildlife Fund and Conservation International. Marc Ravalomanana, Madagascar's president, has vowed to extend its protected area to 10 percent of the country by 2008. Right now, it's about 3 percent. "So it's really a challenge," says Ratsirarson.

Sauther admits, "I used to feel depressed when I came here, because you see the habitat changing and a lot of fragmentation occurring." She says that the government may expand Beza Mahafaly to include surrounding fragmented areas and the people that live in them. "The locals would still use the resources here, but in ways that support both the humans and the lemurs themselves," she says. "So I'm feeling a lot more hopeful than I used to."

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