7: Poo- the notice board of nature

After last week’s discussion on knowledge and respecting other cultures and ways of thinking, I thought I’d go for something a little more juvenile this week- poo! Now, most people can see the enjoyment in watching ducklings quacking away on a lake, or bear cubs rolling around play-fighting in the grass, or even finding rare and beautiful flowers when out for a country walk, but I’ve found over time that expressing genuine excitement over finding animal excrement tends to get some strange looks from people… I don’t blame them, it’s not the classiest of things to get excited about, but poo does tell you a lot about the animal to whom it belongs. This week I want to convince you that I’m not crazy, and explain why animal poo can be exciting and helpful for understanding animals themselves!

Here’s a duckling because, well, I don’t want to have too many photos of poo in here… (Picture: Elinee/Wikimedia Commons/Public Domain)

Fine you strange person, why is poo so interesting?

Humans have an extremely diverse diet. This means that our body is constantly digesting different types of things which pass through our system in different ways and, well, without going in to too much detail, that’s why the end result can vary quite a bit. Animals in the wild however tend to eat a pretty consistent diet, maybe with a bit of variation in the seasons depending on what is around, so their poo generally looks the same. As each species has a slightly different diet and are different in size (think elephant vs. bumblebee bat, whose poo is almost microscopic), you can link the animal to the poo based on how it looks.

Being able to track a species down by its faeces is super valuable. When wildlife film crews set out to film really rare species, like the Amir tiger in Russia, it can take months of sitting and waiting until the tiger strolls by, just for the crews to get a few quick shots of it. You’d hate to be spending those months accidentally waiting in the wrong place, so finding some tiger poo is a really good sign that the animal is around.

So that’s the first thing, poo can tell you if a species is in an area, and as many animals are pretty great at hiding from humans by now, it might sometimes be the only way to know they are there. There are also lots of other ways of tracking animals like looking for footprints in mud or snow, looking at different patches of plants to see where the animals have laid down, or seeing where they may have nibbled on shoots and leaves etc… but you can’t always use these methods, whereas an animal pretty much does always have to poop (though little disclaimer: some snakes only poop once every 3 months so… even this doesn’t work for every animal). You can also tell, roughly, how many animals are in an area by the amount of poo though again I stress the word ‘roughly’. It’s hard to directly predict numbers but you can say by poo volumes that there is more in place A and less in place B.

Rabbit tracks (Picture: Ian Muttoo/Wikimedia Commons/ CC BY-SA 2.0)

Health and diet

Next up, health and diet. Not everything that we eat gets fully digested. For carnivores who might eat small animals whole, they will digest the meat but will excrete the bones and bits of fur, and for herbivores some woody or fibre filled parts of plants won’t get fully digested either. By looking at the poo then you can sometimes see what the animal has been eating recently. If the animal bones are intact enough, you might even be able to work out what species they belonged to before they became dinner for a hungry carnivore.

Moose have a slightly seasonal diet, with winter being full of hard woody plants filled with fibre, and summer being slightly more enjoyable with fresh grasses and shrubs to feast on. This means their winter poo is really hard pellets, and summer poo is a lot more loose. From this you can tell when in the year a moose was in the area.

You can also learn a lot about the health of an animal from its poo, and this can sometimes be far better than examining the animal itself, as it means you don’t have to catch it and it’s not invasive (which can be good both for your safety and in terms of ethics).

On the left we have moose summer poo and on the right winter poo. The summer ones can often be a lot looser, almost like cowpats (Photo: Alaska Department of Fish and Game/Public Domain)

Now the really cool part

For all species, poo is a way of getting rid of waste in our body. However, for many animals it has an important extra function- sending messages. We all know that on a walk dogs will spend most of their time sniffing and peeing on various trees and bits of ground. Each dog has its own distinct scent, so what it is essentially doing is the dog version of carving “I wuz here” on that tree. Other dogs then know that it lives in that area, even if the dog isn’t there to directly tell them. It’s marking its territory.

Many animals do a similar thing with their poo. Eurasian otters tend to have a pretty clearly defined territory that they live and hunt within. They guard it by constantly patrolling up and down its borders, but as their territories can sometimes take days to get from one side to the other, they leave piles of poo at the edges to signpost to others that this is their area. This isn’t all the poo does though.

In one territory you tend to get one male and a few females. Otters are generally loners unless they are raising their cubs, so tend not to hang out with one another, but they still keep in touch. If a male has spent the morning hunting for fish in a certain area, he will leave scented poo on the nearby shore when he goes, so that if one of the females comes by later that day, she knows that the area has been fished recently and there’s not much point wasting her energy there. She may as well walk a little further to where there are lots of fish. Clever huh? Females can also signal to the male that they are ready to mate by smell messages in their poo, and there is probably lots more that they communicate which we have yet to learn. It’s also common for otters to pick a prominent pooping place in their territory where they will all visit at some point, which serves as a sort of message board for the area.

Also, just on a wonderfully petty note: Otters and mink really don’t get on with each other. Mink, who are smaller, will also outline their territory with poo. Sometimes when an otter sees this, they will scrape sand together to cover up the mink poo, making a little sand castle, and then put their own poo on top of this, just as a sort of ‘screw you this is my patch’.

A Eurasian otter munching on some fish. On the right you can see otter poo (called ‘spraint’). It’s so white because of all the bits of bones and shell in it. You can also see the leftovers of the crab it ate strewn about the places. Photos: Author

Waste is useful in other fields too

Poo can tell you a lot about animals: whether they are around, how healthy they are, what they have been eating. It can even tell you what they have been saying to each other. Using the technique of looking at waste isn’t just useful in studying wildlife either. Though the poo has long decomposed, many archaeologists spend much of their time digging through prehistoric bins (called middens) which can tell you a lot about prehistoric people, such as the animal’s bones from their dinner telling you about their diet, to the bits of broken pots that they chucked away telling you about their arts and trading. As they say, one man’s (or woman’s, or animal’s) trash is another man’s treasure.

Also in one interesting case, in the city of York in England, archaeologists managed to find an incredibly well preserved fossilised human poo! This was super valuable to them as from it they could see the remains of the parasites that this particular individual had in their gut, and so could work out the type of diet and diseases that people had back then!

Fossilised viking poo. Jorvik was the old viking name for the city of York. Bet you didn’t think you’d be looking at a picture of viking poo today, isn’t life just full of unexpected adventures! Photo from the Jorvik Viking Centre

Hopefully that has been some interesting info for you and has at least slightly convinced you that being excited about poo isn’t totally crazy! It’s a useful tool, one which I have used in my past research on otters and in my research on reindeer today. Now if you excuse me, I’m off to count reindeer poo- bye!!!

For more info:

How to identify an animal from it’s poo (British/Irish animals though many will be found in other places too!): https://www.discoverwildlife.com/how-to/identify-wildlife/how-to-identify-animal-droppings/

National Geographic article about scents in poo, and in perfume! : https://www.nationalgeographic.co.uk/animals/2018/12/scent-universal-animal-language-and-poo-its-perfume

How some animals likes dogs may use scents from other species’ poo as a camouflage: http://www.bbc.com/earth/story/20170608-the-many-reasons-why-dogs-might-roll-in-smelly-poo

Music: kongano.com

Title image: Andrew Cannizzaro/Flickr/CC BY 2.0

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s