The many (scientific) uses of penguin poop (Part I)

Tracking penguins in (& from) space

Penguins are charismatic animals with a large role in popular culture. They are seen as cuddly (though personally, I think that penguins are from the dark side). Regardless of personal inclination regarding cuddliness, it is easy to see that penguins are unique animals. Something your average penguin fan will think of less often are penguin droppings. These are sometimes also referred to as guano, meaning they have a high concentration of certain elements such as nitrates and phosphates making it useful as a fertilizer (e.g. bat guano is often mined though this practice is controversial). However, penguin droppings, especially those from flagship-species such as the Emperor penguins are hard to harvest. However, penguin droppings have other uses which inspired this series of posts, here’s part I on tracking penguins in (& from space).

Emperor penguins, adult among chicks (from Telegraph.co.uk)

You will have to excuse the little joke in the title – I do so enjoy playing with words. But let’s get down to business. Now that we have agreed that penguins are unique, it seems pretty obvious to want to protect them. One of the things you need to know when protecting a species is where they are. In the Antarctic, getting to a penguin colony is difficult especially as they breed in winter when conditions are even harder.

Recently some clever people realised that they could see penguin droppings from space. Emperor penguin droppings tend to be a brownish-reddish colour so they stand out against the white of the ice. So instead of trekking around in the cold, dark arctic winter, scientists can view some picture while sitting in their warm office sipping coffee. Below is such an image showing a brown stain in creek. That’s what a penguin colony looks like from space.

Of course, it’s not the same as actually going there and doing research on penguins. Reference colonies are needed to establish the number of individuals and breeding pairs etc. But this study does not claim to actually count penguins. This study confirms where penguins are and on top of that, finds a few new colonies. A lot of data about colonies is old. Because it is such a hassle to go to the Antarctic, you’re not going to do it regularly for all colonies. So if a colony has been found, it is not necessarily repeatedly checked upon.

However, if we want to know if climate change or perhaps something else is affecting penguins, we need to know if they’re still there. If numbers decline, eventually colonies are going to vanish. This study took previous data and compared it to satellite images from the early 2000s. The mapped the results and compared them to previously known colonies. Some colonies where newly discovered, some found again and some could not be found, either because they where no longer extant or because the images where unsuitable.

A lot of the colonies that are found again where previously found in the 80s which is a pretty long time ago and it is reassuring that while a handful of colonies apparently no longer exist, about just as many previously unknown ones where discovered in this study. The previously confirmed colonies that could not be found anymore all lie in the areas with slightly higher temperatures (temperatures at colony localities range from -4°C to -20°C). The fact that new colonies have been found in a previously colony-free area shows that emperor penguins are not restricted to some areas of the Antarctic as previously shown, a good thing as a widespread population is more resistant to change. Another fact worth noting is that of the 38 colonies found, 16 lie above 70° latitude. This is the area which has been stated to be most at risk if climate change causes temperatures to rise by 2°C.

Of course, it would be useful if colonies where confirmed on site but in the long run this is a useful and easier way of keeping track of colonies, especially if climate change pushes the ice back faster.

If you are a poop-fan in any sense of the word, please do come back to read about some more uses of penguin poop coming up. Coming soon: Tracking penguins in time.

Text edited: 20/08/2010 due to image problems.

Further links (edited 20/08/2010):

Part II – Tracking penguins in time
Part III – How hard to penguins push?

See also the press release.

Fretwell, P., & Trathan, P. (2009). Penguins from space: faecal stains reveal the location of emperor penguin colonies Global Ecology and Biogeography, 18 (5), 543-552 DOI: 10.1111/j.1466-8238.2009.00467.x