Bruce Congdon, age 12, of Springfield, 111, for his question:
HOW LONG WILL A HIPPOPOTAMUS LIVE?
Third largest land animal in the world is the hippopotamus. The only animals that are larger are the elephants and rhinoceroses. A hippopotamus living in the wilds of Africa has a life expectancy of about 30 years but one making its home in a zoo can expect to live 50 years.
A river hippopotamus is about 12 to 15 feet long and stands about five feet high. Although it can weigh as much as 5,800 pounds, it usually tips the scales at between 2,500 pounds and 3,000 pounds. You might say that they are almost barrel shaped.
The animal's bare skin is thick, measuring almost two inches. The eyes extend out from the head. When resting in a river, often only the eyes, ears and nostrils are above the water's surface. It can even close its nostrils and ears when it dives and swims.
Two Greek words meaning "river horse" have been combined to make the word "hippopotamus.
Many people thought that the hippopotamus sweated blood. This is definitely not true. It does, however, have special glands in the hairless skin that give off a pinkish and oily fluid. This fluid is used to keep the skin from becoming dry and sometimes it looks as if it may be blood.
In addition to the common hippopotamus, which is sometimes called the river hippo, there is a pygmy hippopotamus. This smaller animal weighs from 400 to 600 pounds, is five to six feet long and stands about two and a half feet tall. It spends more of its time in forest areas than in the water.
Pygmy hippopotamuses live alone or in pairs while the river hippopotamuses stay in herds that range in size from five to 30 animals.
A baby hippopotamus, called a calf, will weigh 100 pounds when it is born. Only rarely will a mother produce twins. The calf can swim almost immediately after birth and usually nurses on milk from its mother ¬even underwater.
A river hippopotamus can stay underwater for as long as 25 minutes before it must come to the surface for air. It eats river vegetation during the day, often swimming as many as 25 miles. At night it dines on land plants.
Long, curved front teeth can be found in the hippopotamus' mouth as well as even longer side teeth that form tusks. All through the animal's life the teeth continue to grow. They are never very long, however, because the jaws grind together and wear the teeth away. A hippopotamus' tusks may be two feet in length but only half of this length will stick out above the gum line.
River hippopotamuses can be found in rivers, ponds and lakes in central and southern Africa while the pygmy can be found only in Liberia, Sierra Leone and south Nigeria.
At one time hippopotamuses could be found in all parts of Africa, but they are shrinking in number and are in danger of becoming extinct.