Video transcript
The video is 8 minutes and 2 seconds long.
Produced by the American Museum of Natural History, April 2006.
Visual: Man walks through dense forest, looking up, searching. Cut to lemurs high up in canopy, howling, jumping, responding to other lemur calls.
Speaker: Ian Tattersall, Curator, Division of Anthropology, American Museum of Natural History
I think everybody who's involved with lemurs is concerned for the future.
Visual: Man makes written notes, burning field, pan up from rice field to small village. Deforested area, with title overlay: 'Lemurs of Madagascar: Surviving on an Island of Change.'
Speaker: Ian Tattersall
We're in a finite island that cannot infinitely be exploited and ravaged, and if present trends continue the outlook for any of the natural habitat or any of the lemurs is fairly poor.
Visual: Man speaking in office, followed by map of Madagascar.
Speaker: Ian Tattersall
Lemurs are members of the order Primatis, that is to say the large group of mammals to which human beings also belong. And they're found uniquely in Madagascar and on a couple of adjacent islands of the Comoro group.
Visual: Diverse-looking lemurs in a range of natural habitat.
Speaker: Ian Tattersall
An evolutionary radiation is the diversification of different species from the same ancestor. And once a new kind of organism, like a primate, comes into a new environment, as happened in Madagascar about 60 million years ago, there are many, many different ways in which that environment can be exploited. It's very hard to say exactly how many species of lemur there are because new species are being described all the time, but in general terms there now looks to be about 30 to 35 species of lemurs. And it shows us just what the potential of primates is, to occupy an enormous range of different habitats.
Visual: View of rainforest with mountain in background. Cut to image of construction site, woman walking passed fields of dry terraced agriculture.
Speaker: Ian Tattersall
Habitat destruction takes place on a much shorter timescale than evolutionary change. And the amount of change that's happening so rapidly in Madagascar as a result of human activities is clearly something with which no evolutionary process can cope.
Visual: Man speaking in forest; three men climbing through dense rainforest, looking, pointing, and finally spotting lemur high up in tree.
Speaker: Jonah Ratsimbazafy, Researcher, Coordinator Scientifique, Durrell Wildlife Conservation Trust
Now we are here in Ranomafana, Ranomafana National Park in the southeastern rain forest of Madagascar. This place used to be logged by loggers, but since the park was created the forest started to be protected. Here in Ranomafana, there are 12 different species of lemurs, 7 that are active during the day and 5 that are active during the night. There are many ways of studying lemurs, depends on what you want to look at. I look at their behavior and how the behavior fits with the habitat. For example, we want to know which food and what plants they rely on, because if we can continue to protect the habitat, that will help to protect them or to conserve them.
Visual: Three men observing lemur in tree, one takes notes.
Speaker: Jonah Ratsimbazafy
Every five minutes we take note: what species of tree, who's the closest neighbor, the closest trail, because we want to know where do they go to estimate their home range. And if they eat, what do they eat? Some species cope better than the others. If you're a specialist on your diet and if people cut down your food, you're gone.
Visual: Bamboo lemur in tree, breaking off bamboo stalk and eating.
Speaker: Jonah Ratsimbazafy
For example, the bamboo lemur, that exclusively eats bamboo, and if people cut down those plants they're gone. They can disappear very fast.
Visual: Degraded forest habitat, fields with small village.
Speaker: Ian Tattersall
Different lemurs are affected in different ways by the environmental destruction that's going on in Madagascar. Some lemurs are endangered, some are critically endangered, some are vulnerable, and some are threatened. The less vulnerable ones are the ones that do well in secondary habitats, in habitats that have been altered by people.
Visual: Campsite, woman and man walking through dry sparse forest.
Speaker: Michelle Sauther, Department of Anthropology, University of Colorado
We're at a site called Beza Mahafaly, and it incorporates a protected reserve as well as areas outside of the reserve. And our research here focuses on the effects of fragmentation and changes in habitat on lemur biology and their behavior.
Visual: Woman and man in dry sparse forest, groups of ring-tailed lemurs move across the ground, through forest to more open landscape, and into crops where they begin to eat.
Speaker: Michelle Sauther
We study Lemur catta, which is the ring-tailed lemur. It's the type of lemur most people have seen in zoos. They're one of the most far-ranging of the lemurs. They're incredibly adaptable, and one of the things that we're kind of interested in is what is the biology of adaptation, or what is the biology of avoiding becoming extinct? And because ring-tailed lemurs are so widespread, and that's not to say they're not threatened, but they seem to be able to deal a lot, behaviorally and biologically, with habitat change. I think what we're seeing in terms of the troops we were looking at today is a troop that is actually utilizing some of the anthropogenic change. They will go out and utilize local people's crops, so they're actually exploiting some of the habitat that's been degraded and turned into cropland for their own use. In terms of the ring-tailed lemurs, because they are rather generalist, they do seem to adjust to different types of disturbance.
Visual: Woman and man on camera.
Speaker: Frank Cuozzo, Department of Anthropology, University of North Dakota
As Michelle mentioned a few moments ago, it doesn't mean that we don't have to watch out or think about it, and it doesn't mean there aren't very real threats to long-term survival, but ring-tails specifically seem to deal with things in ways that some of the more specialized lemurs don't.
Visual: Woman and man on camera, lemurs eat from garbage at campsite.
Speaker: Michelle Sauther
But there's always limitations, too. That's what we're trying to understand is where are you when you get to the limits of even a ring-tailed lemur, in terms of being able to adapt?
Visual: Malagasi men shepherding livestock.
Speaker: Michelle Sauther
I used to feel depressed when I come here, because again, you see the habitat changing and a lot of fragmentation occurring. I feel a bit better now because we're trying to really get a handle on what sort of ways you can interact with local people, because that's the reality. What you saw around here is the reality of Madagascar.
Visual: Woman observes lemur with binoculars, lemur leaps from tree to tree high up through dense forest canopy, close up on lemur in tree.
Speaker: Ian Tattersall
I think what we ought to be looking for in terms of conservation is habitats to protect. And what we need to do is to find those places where, with the least disturbance to local people, or to the greatest benefit of local people, tracts of forest that support the native fauna of Madagascar can be conserved.