Just like humans, apes, and monkeys, lemurs are primates. More specifically, they are prosimian (literally pre-monkey) primates, the group with the deepest roots of the primate evolutionary tree. These deep roots mean that lemurs and humans shared their last ancestors nearly 70 million years ago and learning about lemurs gives us some insight into how our earliest ancestors behaved. You may ask, "Why can’t we study other prosimians to get this same knowledge?" Well, primatologists do study the nocturnal bushbabies, tarsiers and lorises, but there is one difference. These other prosimians evolved with and responded to the pressures of the anthropoid (monkey and ape) primates while the lemurs were isolated on the island continent of Madagascar.
About 55 million years ago, in the Eocene epoch, an amazing event occurred that is not fully understood. Lemurs crossed the Mozambique Channel from Africa to reach Madagascar, a distance of about 200 miles. We do not know how, but they did, and in so doing ensured they would be around until today. Monkeys and apes did not make it across and therefore could not compete for the same food resources with their more nimble hands and larger brains that drove the non-Madagascar prosimians to a nocturnal lifestyle to survive. As did Darwin’s finches in the Galapagos Islands, lemurs evolved to fill many different econiches and helped shape Madagascar into the bio-historian’s paradise it is today.
The radiation of life on Madagascar was utterly amazing. Of the thousands of plant and animal species found there, over 90 percent are found nowhere else. From the initial population of lemurs, there was a radiation into 70-plus forms as small as a mouse to larger than a silver-back gorilla. Some are generalist feeders while some specialize in insects or fruit and leaves. Some "hyper-specialize," feeding solely on bamboo (like the panda) or foraging for wood boring grubs (like the woodpecker). Lemurs are among the most diverse groups of animals from common ancestry. But as is so often the case, humans have fouled up paradise.
Madagascar is now an island in crisis. Financially, it is one of the 10 poorest countries; politically, there have been numerous crisis and a recent threat of civil war. The population is about 16 million, which does not seem a lot until you realize half the population is under the age of 18. Lemur habitat is destroyed at an alarming rate in order to feed the exploding population. Estimates put the habitat destruction between 60 and 90 percent, since humans arrived on the island 2,000 years ago; more than half the destruction has occurred since World War II. Among the habitat casualties are at least 17 extinct lemur species, with another dozen poised to vanish within 10 years of conservation efforts fail.
It is within this grim outlook that our foundation sets forth its mission. We maintain a modest colony of lemurs in captivity both for scientific study and to maintain genetic diversity. We focus on species that other captive programs choose not to propagate. We educate via community outreach, the Internet, and collaboration with an in-situ forest reserve. We work with a multinational conservation effort in Madagascar to encourage sustainability, save habitat, and perhaps one day relocate some of our captive lemurs back to their native land.
About the author.Brian Grossi is manager of the Lemur Conservation Foundation in Myakka City.