Mark Pinkston, age 11, of Waynesville, N.C., for his question:
WHAT IS A YAPOK?
He is named for a river in South America. This is rather strange, for the yapok is an opossum and opossums in general are not overly fond of the water. This one, however, spends most of his waking hours swimming and diving for food in his jungle streams.
The opossum and his kinfolk are classed as marsupial animals and almost all of them live in Australia and its neighboring islands. In the distant past, marsupials also populated the other land areas but, as meat eating predators arrived, the gentle creatures failed to survive there.
However, certain opossums did manage to survive in the Americas. One species is at home in woodsy regions of North America and several species enjoy life south of the border. One of the southern cousins is the yapok, alias the water opossum. He is named for the Oyapok River of the Guiana region, though he may be found near the jungle streams all the way from Mexico southward to Paraguay.
The yapok is smaller than our native opossum and quite a bit prettier. His total length is about 26 inches, which includes a ratty tail of 14 inches. His soft thick fur is basically black, handsomely marbleized with cross streaks of silvery white. The toes on his hind feet are webbed and he is the only marsupial who does most of his hunting for food in and under the water.
This water opossum, alias the yapok, lives on the gloomy floor of a dense jungle and often spends the day dozing in a leaf lined hollow. He also has a den quite close to the bank of his favorite stream. He is a born litterbug and the muddy path to his door is strewn with food scraps, such as bones and fish heads.
At night, when his gloomy jungle is even gloomier, he comes forth to swim and dive for frogs and assorted fishy foods in the water. Like other opossums he has 50 excellent sharp teeth and his mixed menu includes dead meat, plus a vast variety of plant food.
The female yapok retires to her burrow to give birth to a litter of helpless babes. The tiny creatures are carried and nursed in the fur lined marsupial pouch on her tummy. It is a waterproof pouch that seals shut when she dives for food.
When threatened, the yapok plays possum and animals who eat only fresh meat leave him alone. Maybe he faints from fright, though recent tests suggest otherwise. Machines that measure brain waves prove that he stays alert and wide awake. So it seems that playing possum is a very clever trick. Perhaps it enabled him to survive in meat hungry regions where all the other marsupials failed.