Edward R. Ricciuti
Adaptations create the astounding variety within the animal kingdom. Some animals are brilliantly colored; others are drab. Some animals are huge; others are so tiny that they cannot be seen without a microscope. Some are slightly unusual; others are utterly fantastic. Some animals share the traits of many animals; others seem to have traits that are quite unique.
The mandrill, a large baboon from Africa, is one of the most colorful mammals. Its face is bright red and blue. Many birds are also brilliantly colored, especially the males. The bird of paradise is one of the most colorful, and beautiful, birds. It lives in the jungles of the South Pacific islands. Its feathers of scarlet, yellow, green, and blue form long trailing plumes or feathery capes. The shimmering colors gleam like metal in bright sunlight. In South America lives a group of frogs, known as poison dart frogs, that are as colorful as any birds. The small animals are bathed in vivid greens, reds, yellows, and black.
The tapir is a jungle animal with an unusual appearance. Big as a pony, the tapir looks like a combination of several animals. It has a body shaped like that of a rhinoceros; a large, tapering head similar to that of a pig; and a nose, or snout, that looks like a shortened version of an elephant's trunk.
The Portuguese man-of-war is an interesting-looking water animal. Its body contains a balloonlike float that acts like a sail. Long tentacles dozens of feet long hang from its body and trail through the water as winds blow the man-of-war across the ocean.
Coral animals, which build reefs by secreting (giving off) limestone, have tubelike bodies with colorful tentacles, resembling petals, around the top.
The Big, the Small
When it comes to large size among animals, most people think of the extinct prehistoric reptiles called dinosaurs. Although not all dinosaurs were large animals (some were no bigger than a house cat), there were some plant-eating dinosaurs more than 85 feet (25 meters) long and weighing 80 tons.
As immense as some of the dinosaurs were, no dinosaur was as large as one animal that lives today. The great blue whale is the largest animal ever known. It grows up to 100 feet (30.4 meters) in length and may weigh more than 130 tons — that is more than the combined weight of thirty elephants. The huge bulk of the whale is supported by water. A land animal of the same size would need such a heavy skeleton and large muscles to support all its weight that it probably would not be able to lift its legs.
Some land animals do reach enormous size. The biggest land animal is the African elephant, which can be more than 13 feet (3.9 meters) high at the shoulder and weigh about 9 tons (10 metric tons). The African white rhinoceros is another heavyweight. It weighs up to 6,000 pounds (2,721 kilograms). Even certain birds can be considered giants. The ostrich, the largest living bird, can tower 8 feet (2.4 meters) high and weigh almost 300 pounds (136 kilograms).
At the other end of the size scale, the smallest animals with a backbone include the goby fish of the Philippines and the Cuban pygmy tree frog, neither of which grows to more than half an inch (0.5 centimeter) in length. The insect-eating shrew, which is the smallest mammal on land, weighs about as much as a dime.