Opossums are the only North American marsupials. A marsupial is an animal with a pouch, like a kangaroo. Opossums have pointed noses and naked tails. They are the only North American mammals with prehensile (grasping) tails. The tail is used to assist in climbing. It also stores extra fat reserves, enabling the animal to survive lean times. Opossums have opposable thumbs on their hind feet which help them to grip branches and climb. They are the only non-primates with opposable thumbs. When baby opossums are born, each one weighs 1/200 of an ounce, is less than ½ inch long, and lacks fully developed hind limbs. Up to 14 young are born after only 12 to 13 days of gestation. Of these 14 young, only about nine survive. The entire litter could fit into a teaspoon. They climb into the mother's pouch, where they remain for about ten weeks. When they are big enough, they ride around on their mother's back. When attacked, an opossum can play dead, or "play possum." When using this defensive strategy, they drool and emit an unpleasant smell which discourages predators. They also climb to escape danger. When threatened, they will hiss and show their 50 sharp teeth. They nest in abandoned burrows or fallen trees. Opossums eat a variety of foods and are able to adapt to many different environments, from cities to wilderness. Their tracks show five toes on the front foot and five toes on the rear, including the opposable thumb. The thumb lacks a claw.
Click here to see drawings of opossum tracks.
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