Audio Transcript:

Marco Werman: I am Marco Werman and this is The World. There's been a lot of criticism of the use of drones in America's foreign policy, but now scientists are experimenting with drones in a completely different way. They're using the unmanned aircraft to try to protect orangutans on the Indonesian island of Sumatra. The World's science correspondent Rhitu Chatterjee joins me to talk about these Conservation Drones and, thank goodness Rhitu, the drones are going to protect the orangutans but, why drones?

Rhitu Chatterjee: You see Marco, unlike other great ape species like, say, chimps or gorillas, orangutans are tree-dwelling animals so they're a little harder to study. I spoke with primatologist Serge Wich, the guy behind this new idea. He is at Liverpool John Moores University in the U.K. and he says the way he monitors orangutan populations is by counting nests that are high upon trees.

Serge Wich: Orangutans make a nest almost every day at nighttime and by counting the nests we can estimate the orangutan density.

Werman: Right. I got it. So, if you're doing the survey on foot, you're gonna have to somehow get high up in those trees.

Chatterjee: Or, count them from down below. So it's a difficult task, right, and it's time-consuming and it's expensive. Wich told me that his last survey cost him about $250,000 and that's why he thought, "Well, why not try drones?"

Werman: Right. And drones are actually cheaper?

Chatterjee: Definitely. A single drone costs only about $3,000 to $4,000 and you can cover a big swath in, say, half an hour.

Werman: Right. And so, when they take these photographs…these drones, are they photographing the primates themselves or their habitats, or nests like you're talking about?

Chatterjee: So, the drones are taking pictures of everything and they include the nests and if there are animals on it they get pictures of that as well. Then, when the drones come back, they can retrieve the pictures. I also believe that the latest drone that they have used has a video camera capable of transmitting back the images live. So, as the drones are up in the air, the scientists can see what it's seeing.

Werman: So, you get a lot of data collection, you get these live video feeds and some great photographs of the orangutans and their habitats. How does this actually help save the species though?

Chatterjee: So, you have a better way to monitor the species population. You're doing it in over much shorter periods of time so any fluctuations in the population you can get a better sense of it much more quickly. But the drones are bringing back a lot more information than just these animals and their nests. They're helping keep track of other activities — human activities in the forest. Here's Wich again.

Wich: We can see illegal activities such as logging on the photos. We can see agricultural uses on the images. We can, for instance, see if somebody is planting corn or oranges. So, you get an enormous amount of detailed information from the images that these drones capture.

Chatterjee: And all this information will help him and his colleagues and the Sumatran authorities reduce the threats to orangutan population including, perhaps in the future, poaching.

Werman: Well, fascinating. Orangutans and the natural world around them — thanks to Conservation Drones. The World's science correspondent Rhitu Chatterjee, thanks for stopping by.

Chatterjee: You're welcome, Marco.

Werman: And you can learn more about these Conservation Drones. Rhitu has a whole interview with Serge Wich on her Science podcast. You can download it at