In observance of Thanksgiving week: How do wombats poop cubes?

Answering the unspoken question, yes, we are a little feverish here in the guild headquarters. Science News answers the explicit question, however. By having very limber wombat intestines:

The varied elasticity of the wombat’s intestines helps the marsupials to sculpt their scat into cubelike nuggets, instead of the round pellets, messy piles or tubular coils made by other mammals, researchers reported November 18 at the American Physical Society Division of Fluid Dynamics meeting in Atlanta.

Wombats mark their territories with small piles of scat. Cuboid poops stack better than rounder ones, and don’t roll away as easily.

When an Australian colleague sent[Georgia Tech mechanical engineer David] Hu and his colleague [study leader] Patricia Yang the intestines from two roadkill wombats collecting frost in his freezer, “we opened those intestines up like it was Christmas,” Hu says.

The intestines were packed with poop, Yang says. In humans, a poop-filled bit of intestine stretches out slightly. In wombats, the intestine stretches to two to three times its regular width to accommodate all of the feces.

The finished turds are especially dry and fibrous, which may help them retain their signature shape when they’re squeezed out, Yang suggests. They can be stacked or rolled like dice, standing up on any of their faces. (She knows. She tried it.)

In the wild, wombats deposit their droppings on top of rocks or logs as territory markers, sometimes forming small piles. They seem to prefer to poop in elevated spots, Hu says, but they’re also limited by their stubby legs.

To confirm that the elasticity variation really does form the cubes, Yang and Hu are now trying to model the wombat digestive tract using pantyhose.

Of course, you need the citation, right? Here’s Yang’s presentation at the 71st Annual Meeting of the APS Division of Fluid Dynamics.