Going through the sample freezers in the lab here at the University of Calgary made me think about the importance of poop for conservation – mainly because the freezers are stuffed full of feces from a variety of wild animals.
Anyone who has talked to a wildlife ecologist knows that we like to talk about poop – a lot! Many dinner parties have in fact been dominated by different poop collecting stories, to the horror of non-science friends. What is it with our fascination with animal droppings that lead them to being incorporated into so many studies? There are several reasons, one being the ease of collection and another the wealth of knowledge that can be obtained from poop.
When studying elusive free ranging wild animal populations, one of the biggest obstacles in data gathering is accessing your sample population. If, like in my case, you add a threatened species, remote locations, expensive transportation, freezing temperatures, transboundary issues and unpredictable weather conditions to the equation, things tend to get a bit complicated.
However, by following animal tracks and collecting fresh fecal samples we can gain access to a lot of information, without disturbing the animals. If we GPS tag these locations, and record the date of collection, we can couple environmental data with individual animal data.
Below are some examples of the awesome things you can learn from poop.
Who’s there? By looking at the colour, shape and size of droppings you can identify which species it belongs to. For instance, hyena dung is white due to the presence of high levels of calcium, a result of hyenas eating the bones of their prey, whilst lion dung is black due to the amount of blood they consume.
What’s for dinner? Droppings can tell us what animals have been eating. For example, to find out if the endangered African elephant and black rhinoceros compete for food, researchers at the Centre for African Conservation Ecology studied rhino and elephant poop in different seasons to see what they are eating, and if the diets are different when elephants and rhinos share the habitat compared to when rhinos are alone.
How many? By counting the number of droppings in a set area you can estimate population density. For example, a 10 year study that counted snowshoe hare pellets showed that pellet counts strongly correlated with hare density. The snowshoe hare is the primary food of lynx, and is critical for its survival. The lynx and snowshoe hare cycle are closely connected, where the lynx population rises and falls with the hare population. Thus, by counting snowshoe hare pellets, researchers gain information needed by land management agencies for hare AND lynx conservation.
How stressed? When animals are exposed to physiological or environmental stress, hormones are released and eventually excreted in feces. As part of my research I am measuring the level of stress hormones (glucocorticoids) in fecal samples from caribou and moose to determine if these correlate with other health indicators such as parasitism and body condition. We are hoping that stress hormones will eventually be useful as overall bio-markers of health.
How hungry? By analysing poop for different hormones we can gain insight into the nutritional state of the animal. For example, as part of a study investigating the impact of wolf predation and human activity on moose and caribou in the Alberta oil sands, Wasser and colleagues trained dogs to find caribou, moose and wolf scat. These samples were then analysed to measure the levels of thyroid hormone metabolite, which decreases under nutritional stress.
Which parasites? Poop can be used to identify and monitor many different parasites. For helminths (parasitic worms), this is often done by counting the number of eggs in the feces.
Who’s who? Fecal samples can also be used for genetic studies and to help us identify the species, sex and individual identity of animals. One of my collaborators, PhD student Jean Polfus, is currently conducting a genetic study on woodland caribou in the Sahtu to determine how closely they are related to each other. She does this by collecting poop samples and analysing the mucosal layer surrounding the sample.
Not the whole poop scoop
Poop is not only a gold mine for information but also plays important roles in ecosystems. Whale poop, for example, is important for primary productivity in the oceans due to its high content of nitrogen and iron. This means that more whale poop leads to more plankton, which leads to more fish.
I could go on, but I think I’ve already illustrated that there is more to poop than meets the eye – it’s not just a pile of shit!