Virginia Opossum

Didelphis virginiana

The only marsupial native to the United States and Canada, the Virginia opossum is an exotic species for the central coast region of California. Reportedly brought to the region in 1895 as a game animal, the opossum has since done quite well in the area if the abundance of roadkill carcasses strewn along the highways is any indication.

The Virginia opossum looks like a large rat with its hairless, prehensile tail and long snout. It is a nocturnal and usually arboreal animal that hisses when confronted or even goes into a catatonic state (plays possum) when put under a lot of stress.

Alden M. Johnson, California Academy of Science
Since the opossum is a marsupial, its young (as many as 20) are "born" after an extremely short gestation period of as little as 11 days in an under-developed state and must crawl up the belly to the pouch where they attach themselves to the only thirteen available nipples. The surplus young who cannot find a nipple perish. The oppossum babies stay attached for two to three months of further development and then spend another one to two months with the mother until they are ready to go solo.

Since the reconnection of South and North America by the Panama land bridge around 3 million years ago, many species of animals have migrated between the two continents. Camelids, canids and felids went south whereas opossums, sloths, anteaters and armadillos came north. Since the opossum is primarily arboreal, it is not surprising that the marsupial could not traverse the deserts and grasslands of the west to populate the forested regions of California and the Pacific Northwest, that is, until they were brought in by people to be used as game animals in the late nineteenth century.

At right we can see the toothy grin of an opossum skull. Indeed, the opossum with 50 has more teeth than any other land mammal in North America. Notice the small volume available for enclosing the brain. Notice, too, the large openings encircled by the zygomatic arches. The opossum seems to be much more jaw muscle than brain.

The word opossum is one of the oldest indigenous American words in the English language. Promotional literature of 1610 extolling the virtues of Jamestown, England's first settlement in the New World, spoke of the wild "Apossouns, in shape like to pigges"-- apossoun being Algonquin for "white beast."

Coe Park specimen photo Kenneth Adair