Antarctica: Penguin Population Double Previous Estimate

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This story is based on a radio interview. Listen to the full interview.

Audio Transcript:

Lisa Mullins: I'm Lisa Mullins and this is The World. Think climate change and many people think penguins. The birds have become the emblem of the threats posed by climate change. That's because the Habitat of several penguin species in Antarctica is literally melting away, but forbidding conditions there can make it pretty tough for scientists to know just how many penguins are actually there these days. Now satellites and digital technology are helping researchers get a better grip on penguin numbers, and at least for now for one species, the news is good. Michelle LaRue is coauthor on a new study on emperor penguins. She is a research fellow at the Polar Geospatial Center at the University of Minnesota. Give us the good news, Michelle.

Michelle LaRue: Well the good news is that we have a first ever full census of the emperor penguins which of course were made famous by the movie The March of the Penguins. And what we were able to find is that there are 595,000 emperor penguins in Antarctica which is about twice as many as previously suspected.

Mullins: So how'd you find out the good news?

LaRue: Well, what we did is use high resolution satellite imagery so what we were able to do is kind of zoom into some of the locations where you would see a brown stain on the sea ice, and that's an indication that there's an emperor colony there.

Mullins: This is guano.

LaRue: That's right, yep, this is their guano, so by zooming into the locations of their guano we were able to actually see the individual penguins and then train the computer to differentiate the differences between the individual penguins, the guano that they're sitting on, and then the surrounding ice.

Mullins: So interesting though that you see the guano first and then the penguins, and then you can count. Does that mean that you counted every single penguin there?

LaRue: We were able to count roughly half and so our estimate is about 238,000 breeding pairs. And when we were counting the individuals at a colony, that is half of the adults that are present at the colony because the other half are foraging at sea. The satellite imagery allowed us to find seven new colonies that we didn't even know existed and so it's really being able to have that remote access to some of these really dangerous areas to get to and harsh areas to get to that allowed us to count the entire population of emperor penguins.

Mullins: So it's kind of a super version of Google Earth.

LaRue: That's right, yep, and Antarctica and studying emperor penguins is about the most perfect test case you could have for doing this kind of a thing. It's white sea ice. They have a brown guano stain. There's nothing obstructing our view, there's no trees in the way. And so it's very easy to be able to see them, there's nothing else it could possibly be when you see the brown guano stain on the sea ice. There's nothing else it could be other than an emperor penguin colony.

Mullins: So you have asserted as have other researchers that the climate change has indeed affected the population of emperor penguins. Does this tell us that maybe the threat isn't as bad as you all thought?

LaRue: No, not necessarily. And the reason I say that is because the population estimates prior to this were incomplete. To be clear, what this research means is that we have a full estimate finally. Just because we know that there are double the amount of penguins than we previously thought doesn't mean that population doubled; it just means that we know they're are more than we previously thought. And so the threat of climate change is still the same as it was before. We do know for sure that there is one colony that's already gone. At the Dion Islands in the Antarctica Peninsula where the sea ice is no longer there during the key times when they need to be sitting on the sea ice. So we already know that loss of the ice has had a huge impact on at least one colony.

Mullins: All right, where are you gonna set your sights next, Michelle?

LaRue: Well, the nice thing about this high resolution imagery and one of the cool things about this study is that for now we know that we can do this and now there's many ays we can move forward. First of all, we can start to monitor the populations of emperor penguins through time, but we can also see what other applications this could have for other populations of animals in Antarctica, such as Weddell seals and maybe some of the other types of penguins that are in Antarctica as well.

Mullins: Michelle LaRue, a research fellow at the Polar Geospatial Center at the University of Minnesota. She has coauthored a new study on emperor penguins, just published in the journal PLoS ONE. Thank you very much, Ms. LaRue.

LaRue: Thank you.

Mullins: We've got a link to the study as well as some great photos of the movie star penguins online at