Scientists have stuffed balloons into dead wombats to find out why they poop cubes

By Cleve R. Wootson Jr. | The Washington Post

Among all the adaptations that allow our animal brothers to fly in the air or to withstand the darkness and overwhelming pressure of the depths of the ocean, there is a unique property in the animal kingdom.

Only wombats can produce cubic poop.

Think about it, although preferably not while eating and certainly not aloud: Among all the animals you can imagine, which one produces flat feces on all sides and can reasonably be used to interrogate students in geometry?

But how is it? And does this provide an evolutionary advantage to wombats when they take a trip into the circle of life?

These questions on Wombat poo have made scientists puzzled since the researchers who studied the Wombat Hoop existed and the answers have escaped humanity until this precise moment in human history.

We now have answers, which are clearly related to the nature of Australian animals.

Gauging wombats only at sight, marsupials are what scientists would officially call hugs. But in the wild, they are actually pretty aggressive and territorial – cousins ​​basically nuts of koalas.

Although it's rare for the wombats to attack humans, YouTube videos are brimming with muscular marsupials attacking zookeepers, whistling and sniffing stunned videographers and animators of BBC animal shows. In 2010, an Australian was forced to kill a wombat with an ax after finding the aggressive marsupial waiting on his doormat.

"Apparently, he attacked his leg and knocked him down and started attacking his chest, then Brucey killed the wombat and was taken to hospital in an ambulance," said a witness at the Australian Broadcasting Corporation, which stated that the wombat may have been in the advanced stages of scabies.

If a wombat meets a strange wombat or predator in the wild, it is not uncommon for the fur to take flight.

Yet, wombats are not eager to fight. They are herbivores that persist on roots and other plant material, and only attack when threatened. Most of the time, they just want to be left alone.

That's where the shit comes in. The wombats produce up to 100 cubes of poo every night and surround their labyrinthine shelters to serve as an anti-intrusion sign to the other wombats – a border wall made from poop, according to National Geographic. The wombats are nocturnal and have poor eyesight. The wall is therefore essentially composed of odors.

The wombats who are better able to deter unwanted aliens are more likely to avoid conflict and injury, and therefore increase their reproductive success, according to the magazine.

But shit rolls and can not stay in place on the ground or on the logs and rocks that dot the Wombat landscape.

Still, determining the biological mechanics of transforming wombat shit into a cube has taken a particularly complex science.

Patricia Yang, a postdoctoral fellow at Georgia Tech, has devoted her young career to studying, in great detail, the biomechanics of how animals poop and urinate.

In 2013, various publications wrote about her research on urination of mammals (selected titles: "How fast does an elephant piss?", "New Law on Urination: Mammals Take 20 Seconds to Pee" and "The other rule of gold"). Last year, she deepened "the hydrodynamics of defecation".

Much of her research has led her and other students to the Atlanta Zoo and slow-motion video of pooping and peeing animals. For science.

The study of how nature has solved some of the problems of physics is a separate branch of the design called biomimicry. The excretion of urine and feces is a biological function, but it is also a physical action, using energy and structures specially designed to move solids and liquids.

The urinary tract of an elephant, for example, can move nearly half a tub of water in 20 seconds. As Yang says in her thesis, this is an example of "evolving hydrodynamic systems". Studying how an elephant empties its bladder can provide guidance on how to make a better fire hose or sewer pipe.

Biomimetry is particularly useful when designing more energy-efficient and less expensive systems. What is a solar energy user more effective than a blade of grass?

But to understand the inner workings of the wombats, Yang had to do much more than set her video camera in slow motion and avoid the suspicious zookeepers.

According to the abstract of his article, Yang and other researchers found dead wombats struck by cars in Tasmania and euthanized by a veterinarian.

They emptied the dietary routes of the animals and filled them with a balloon, which they used to study the pressure exerted by the walls of the intestine. As a control, they also inflated the intestines of pork.