Snake eaters of the wild

Opossums are native to our area and even have a road named after them — Opossumtown Pike.

Opossums are nocturnal and omnivorous; they eat almost anything, including rodents, amphibians, snakes, insects, fruit, seeds, carrion and garbage. They will attack and eat rattlesnakes and copperheads.

Credit: maryland.gov - Bob Gress

The opossum (Didelphis virginiana) is a marsupial, which means it is in the family of mammals whose young are incompletely developed at birth. Female opossums, like most marsupials, have a pouch in which the young can feed on mother’s milk and develop further after birth.

Recent research shows opossums possess a gene that enables production of a blood protein that counteracts the anti-coagulating effects of poisonous snake venom. It is thought that snake venom has likely evolved to defend against predators, such as the opossum, and not primarily to help the snake obtain prey. Opossums, on the other hand, have evolved a gene that provides immunity to rattlesnake and copperhead venom.

Opossums in our area mate during the winter and give birth after a short gestation period of about two weeks. While there may be a dozen or more in a litter, some newborns fail to attach to teats in the pouch. The remaining young develop over the following three months. After weaning in the spring, they leave the pouch.

Opossums have prehensile tails that can help stabilize them while climbing. Although the tail is not strong enough to support an adult’s weight, the tail is sometimes used for carrying leaves or sticks for nest building. Opossums also have opposable big toes for grasping.

The typical response to threats causes the opossum to lose consciousness, drool saliva and secrete a noxious fluid from anal glands, mimicking a dead animal. Playing dead, or ―playing ’possum,‖ is not a conscious act by the animal but rather is involuntary, much like fainting. Opossums will also hiss or growl when threatened.

While their immune systems are stronger at resisting rabies than those of many other small mammals, a few are found to be carriers of rabies. Like other wild mammals in our area, it is best to avoid them, especially if they are acting strangely.

Article by FCFCDB

Nature Notes for 12/11/2011