The koala, like the kangaroo, has a pouch that is in the front. However, unlike the kangaroo, its opening is oriented to the rear. This is usually found in burrow and aquatic dwelling animals, such as the wombat, as opposed to arboreal (lives in trees) animals, such as the koala.

So how does this type of pouch benefit the koala?

Baby koalas, also known as joeys, must eat Pap, a special blend of their mother’s feces. The practice of eating feces is called coprophagy. While this may sound disgusting to you and I, it is vital for the joeys to be introduced to the micro-organisms needed to digest the typically toxic eucalyptus leaves. The micro-organisms come directly from their mother’s digestive system via the pap. The rear-oriented pouch opening facilitates the necessary practice of coprophagy and thusly, serves the koala’s needs for survival.

The interesting point to investigate is where this pouch evolved from and where does this point for the evolutionary history of the koala?

If you have more information on this than we do, we’d love to read about it and discuss it with you.

Sources:
http://www.thekoala.com/koala/
http://darwinstories.blogspot.com/2008/05/how-koala-got-it-backwards.html