Yes, today we’re taking a closer look at animal poo, along with some extraordinary adaptations. If you’re just about to sit down for lunch, you might want to bookmark this one for later. But if you think you can stomach it, read on for some nuggets of information from around the animal world!

Why do sloths defecate on the ground? Why is wombat poo square?…and why would you really, really not want an Adélie penguin as a neighbour?

Sloths and their perilous preference

For a sloth, survival hinges on one strategy: a low-energy lifestyle. Their main source of food is leaves, which aren’t very nutritious at all. They move slowly and as little as possible, because their diet simply doesn’t allow them to do otherwise.

Gripping a branch with their long claws, they spend most of their time up, away from predators, in the safety of the canopy. However, once a week, they consume an enormous amount of energy, climbing down to defecate on the forest floor.

On the ground sloths are extremely vulnerable. So why take such a risk? Nobody is 100% sure. The leading theory links the behaviour with the presence of sloth moths, which live exclusively in sloth fur.

There is a strong symbiotic relationship between the moths and their sluggish hosts. Not only does the sloth provide a place for the moths to live, it also gives them a warm place (the sloth’s faeces) to lay their eggs. In return, these insects help cultivate and fertilise algae in the sloth’s fur, effectively covering it with green camouflage and providing them with complementary food.

Happy brown-throated sloth (Bradypus variegatus). By jdross75 |
Happy brown-throated sloth (Bradypus variegatus). By jdross75 |

Wombats and their square poos

As you can see from the photo, wombat poo is not perfectly square-shaped. That said, compared to that of other animals, it is surprisingly cubic!

How do they do it? It’s all down to what they eat – mostly grasses and roots. This type of vegetation is tough and can take up to 18 days to digest. In this time the wombat absorbs as much water and nutrients as possible, leaving a waste product that is dry and very compacted.

For most mammals, during defecation, faeces is shaped by the rectum. In the case of wombats, their poo is too hard for this to happen, so it comes out as little blocks (probably molded in the first part of their intestine, with horizontal ridges that absorb nutrients). Take a look at The Wombat Foundation for more info about this awesome animal.

Cute Wombat feeding on grass and Wombat Poo, Cradle Mountain. By Lucas T. Jahn and Pixelheld |
Cute Wombat feeding on grass and Wombat Poo, Cradle Mountain. By Lucas T. Jahn and Pixelheld |

Rabbits and their unsavoury eating habit

Don’t be mistaken in thinking that rabbits are rodents – they’re not! Along with hares and pikas, they belong to the lagomorpha order. While rabbits enjoy a more varied diet than wombats, efficient digestion of vegetation is still a challenge.

Instead of digesting their food over an extended period, rabbits digest their food twice. That’s right, they eat their own poo. More specifically, they produce special, nutrient-rich cecotrope, also known as ‘night faeces’. It may not sound too pleasant, but it’s a crucial adaptation that ensures their survival.

Adélie penguins and their anti-social practices

Speaking of unpleasant, let me introduce you to the Adéle penguin. Named after the wife of a French explorer, these striking seabirds are common along the Antarctic coast. They may look cute, resembling little men with tuxedos, but don’t get too close.

With adults reaching 70 cm in length and around 5 kg in weight, there’s not much risk of getting hurt. But, if you stand too close to one, you have a good chance of getting splattered!

Adélie penguins are masters of the projectile poo, as the video graphically shows. They are capable of generating remarkably high pressures in order to send their faeces far from their well-kept nest…though sometimes in the direction of an unsuspecting neighbour.

White admiral caterpillars and their clever camouflage

As a butterfly, the white admiral has spectacular black wings with distinctive white bands. But before it reaches that stage, it must survive two precarious weeks as a caterpillar.

How does it survive? An extraordinary adaptation means that the caterpillar resembles bird droppings. Considering that birds are its main predator, this is an especially effective camouflage. Unlike our lagomorphic friends above, no self-respecting bird is going to eat something that looks like its own poo.

This adaptation is complex as it combines anatomical factors, such as shape and colour, as well as behavioural factors. More specifically, the caterpillar uses silk and its own excretion to enhance its camouflage. The result? Success and survival. In other words – natural selection.

white admiral caterpillar on an aspen branch. By Tyler Fox |
white admiral caterpillar on an aspen branch. By Tyler Fox |

This post was inspired by Alastair, a little boy with a passion for animal poo!

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James is a freelance language professional based in Barcelona. Besides writing articles for Zoo Portraits, he writes about education and teaches English as a foreign language in businesses, universities and other institutions around the city.


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