Why Do Koala Pouch Bears Excrete Square Poop? Is Its Intestine Square?

Yes, you haven't heard wrong, nor have you seen wrong, this block that looks like 'brown sugar' is bear possum excrement.

Excrement belongs to excretion, no matter how small it is for invertebrates, or how big it is for African elephants, every species will have excrement, and the shape of the excrement is also many kinds, such as water droplet shape (rabbits and sheep), tubular shape (dogs), and board-shaped (cows). However, the bear possum is unique in this regard, because it can excrete block-shaped excrement.

The bear possum is a native Australian animal with a pouch, stout in body like a bear, squat and chubby, famous for its cute appearance.

It is a solitary nocturnal animal, spending the day in underground caves, and coming out at night to eat grass and other plants, sleepy,

It sleeps an average of 16 hours a day.

Because the bear possum is a nocturnal cat, its vision is very poor, so it relies on its sense of smell to navigate and find food.

So, what is excrement used for?

Various species have adapted to use excrement in different ways, such as spreading seeds, or as food for animals like dung beetles.

Excrement can also provide other information. Different materials, sizes, shapes, and smells can help identify species, and using this information can also be used to investigate elusive animals, such as we can study dinosaur excrement fossils to study dinosaur habits.

However, excrement is also smelly, so it can be used for communication and marking territory.

The bear possum has a strong territorial awareness, so it uses block-shaped excrement to mark its territory to avoid conflict.

A bear possum can pull out 80 to 100 blocks of block-shaped excrement in one night, each with a diameter of about 2cm. The bear possum is very obsessed with its excrement, it will collect them and put them in places where other bear possums can easily find them, such as outside the cave, rocks, and logs.

This tells us who lives here? Are there strangers nearby? Do we need to guard against enemies? Is the female bear possum in estrus?

The most important thing is that the cubic excrement is an advantage, its unique shape ensures that it can be stacked one by one without rolling.

But how are block-shaped excrement produced?

The bear possum's excrement is block-shaped, obviously not because its anus is square.

First, it is related to its digestive tract.

The bear possum has a very long digestive tract, and the digestion process is very long and slow, generally 14 to 18 days, which allows the intestine to absorb as much nutrition and moisture as possible from the food, resulting in very dry and compact excrement.

Secondly, the bear possum's intestinal elasticity is different.

Scientists conducted experiments on dead bear possums, they emptied the intestines and inflated them, they found that the pressure experienced by the excrement from the beginning to the excretion increased significantly, from the initial 20% to 75%, which is different from the elasticity of the pig's intestines, so the excrement cannot continue to maintain a tubular shape.

Thirdly, scientists found that the bear possum's intestinal first part is a horizontal striated structure, these striated structures may shape the excrement into cubes, while the last part of the large intestine is relatively smooth, which can maintain the cubic shape.

In general, the striated structure and the compacting properties of the excrement prevent the intestine from shaping the excrement into a more common tubular shape.