July 22, 2013

Fastinating Facts about Opossums

By Rachael Sitzer, Program Intern

In the short amount of time that I have been interning at Squam Lakes Natural Science Center, I have learned that opossums are far more interesting than I ever expected. And yes, it is important to pronounce the “o” in “opossum.” In fact, there is an entirely different group of marsupials called possums, which are found mainly in Australia. Possums and opossums are not closely related other than the fact that they are both marsupials.

Opossums are the only marsupial found in either North America or the northern hemisphere. The Virginia Opossum (Didelphis virginiana) that we commonly see in the United States is the only species of marsupial found north of Mexico. Appropriately called a “living fossil,” the opossum dates back 70 million years and lived during the age of dinosaurs! The only other mammals that have been around longer than that are the egg-laying monotremes, including the echidna and duck-billed platypus. Opossums may not have large well-developed brains, but they clearly have some survival skills that have kept them here this long.

The opossum’s rat-like appearance is partially due to its scaly, hairless tail. Like a monkey, the opossum possesses a prehensile tail, which can be used to grip objects (not to hang by!) If you have ever had a chance to see an opossum’s tracks in the snow or mud, I guarantee you will never forget it. Their front feet have five evenly spaced toes that somewhat appear like a star, while the hind feet have an opposable thumb-like digit that gives the overall appearance of a monkey’s foot. With a life expectancy of up to two years in the wild, opossums have no time to waste.
A gestation of only 13 days helps females raise two litters in just one year. When born, an entire litter can fit into a teaspoon and each can grow to weigh 28,000 times its birth weight! Although opossums can flash a set of 50 menacing teeth (more than any other land mammal!), they actually tend to be more shy than aggressive, hence the behavior of “playing possum.” It is in fact true that opossums sometimes fake death in order to avoid becoming the meal of a predator.

The unique, even strange, characteristics and qualities of the opossum have surpassed my previous preconceptions of this unknowingly exceptional animal. I never would have imagined that I could find an animal as simple and common as an opossum so fascinating!

1 comment:

Ines said...

This is great!