Today the Galapagos tortoises are in danger of being totally exterminated. They apparently lay very few eggs and these as well as the young turtles are destroyed by the rats, wild dogs, cats, and other animals which man has introduced into these islands. Some of them can be seen in zoos, but they have seldom bred in captivity.

The desert tortoise, found in western American deserts, is related to the Galapagos tortoise but it is much smaller, only about ten inches long. These desert tortoises, like their larger relatives, eat cacti. They are not active during the heat of the day, but rest in underground hiding places. When the temperature falls in the evening they come out to feed. During mating season the males often have battles over the females. They try to tip each other over and one is sometimes successful. With a great deal of effort a tortoise can succeed in getting back oh its feet, but in the meantime the victor has gone off with the female.

Turtles which live in a completely different environment are the sea turtles. The largest of these is the leather back which may be six to eight feet long and weigh over a thousand pounds, although turtles of this size are rare. The green turtle, caught commercially for food, may weigh four hundred pounds.

Most sea turtles live in warm ocean waters. Their legs have become modified into flippers so that they can make rapid progress, sometimes reaching a speed of twenty miles through the water. They still need to breathe air and must come up to the surface at least every few hours. Sea turtles return to land to lay their eggs. The female laboriously crawls up on a sandy beach and digs a hole in which she may deposit as many as one hundred eggs. Then she covers them with sand, and goes back to the sea.

The eggs hatch from one to three months later and the tiny young turtles get down to sea as fast as they can. Many young are lost to predators such as gulls, ospreys and large fish. In some regions turtle eggs are considered to be a great delicacy, and people dig them up. Because of the decreasing numbers of sea turtles, an effort is being made to protect them, and it is unlawful in many places to disturb their nests.

There are also turtles which live in fresh water. One of the most fascinating of these is the alligator snapper, which lives in the southern part of the United States. The alligator snapper may measure more than two feet in length and may weigh one hundred and fifty pounds. It spends its life almost entirely in the water; only the female comes out to lay her eggs on land.

The alligator napper has its own built- in fish lure—a projection on the front of its tongue which looks like a wiggling worm. Any fish that investigates this lure is apt to become food for the turtle. Turtles are the oldest living order of reptiles. Their ancestors were on earth two million years ago, even before the dinosaurs, and present-day turtles have not changed very much since then. It is thought that their shell has aided their survival.

All of them lay eggs and all of them have shells. This shell, covered with horny plates in most species and with leathery skin in others, is the turtle’s defence against its enemies. Because of this heavy shell, a turtle moves slowly on land. A tortoise can travel about one quarter of a mile in an hour, if it does not decide to rest on the way. Turtles are cold-blooded, which means that their body temperature is regulated by the temperature of the air. For this reason they are not found in very cold climates, and must hibernate during the winter months in temperate regions.

Those that live in hot climates cannot stay in the sun—they would die if exposed for any length of time to a temperature above 110° F.—and must hide in shaded or cool spots during the day. Yet with luck, turtles can live to be older than most other animals. There is a record of one tortoise in captivity that lived to be one hundred and fifty years old. In the United States the word turtle is usually used to refer to those species which live largely in water; the word tortoise to those species which live entirely on land. There are about two hundred species of turtles found in the world today.

Turtles Pictures

The anoles are a fascinating group of iguanas. They are found in tropical or subtropical regions. Depending on the temperature and light, they can change their colour from brown to green. The males have a red skin flap on their throats which they inflate during courtship or as a warning to other males to keep out of their territory. The largest iguanas are the common iguanas which live in tropical Central and South America. They may be as long as six feet including their tails, but the tails account for about two-thirds of the total length. They look like animals which have survived from the earliest days of the earth.

Common iguanas are vegetarians; they eat leaves and fruit. With their strong claws they can easily climb to the highest limbs of the tropical forest trees. The females lay their eggs in the ground; the young iguanas hatch in about two months. People who live in the regions where the common iguanas are found consider them to be a great food delicacy. The iguanas, however, are not easy to capture since they can escape by climbing, by running, or even by swimming. Two of the rarest iguanas live in the Galapagos Islands off the coast of South America. The first of these is the marine iguana, the only iguana which feeds on seaweed. One of their favourite foods is sea lettuce. They are excellent swimmers, but usually feed close to shore at low tide. After they eat, they spend the rest of the day basking in the sun along the rocky coast.

Most of the marine iguanas are blackish like the volcanic rock on which they live. However, on some of the islands the iguanas have patches of red or green during the mating season. At this time too, there are apt to be head-butting battles between males and even between females looking for places in the sand where they could lay their eggs. Each female lays only two eggs—some other species of iguanas may lay as many as eighty eggs—which hatch in about two and a half months. Newly-hatched marine iguanas are about ten or eleven inches long; adults may be from three to four feet in length.

The other Galapagos iguanas are the land iguanas which are from two to four feet long. They Jive on cacti and other plants. Their numbers have been greatly reduced by dogs, by pigs which eat iguana eggs, and by humans who use them for food.

There are two species of land iguanas found on different islands of the Galapagos. In one species the males become red and yellow during certain seasons; in the other species there is no colour change from the usual yellowish-brown. In 1964, leading scientists of many countries established the Darwin Research Station in the Galapagos. One of the purposes of this biological station is to find out, by studying various plant and animal interrelations, what conservation measures are necessary to save the rare and unique animals of these islands, including the land iguanas.

There are now thriving colonies of these only on two of the eight islands.Both the marine and the land iguanas of the Galapagos were first described by Charles Darwin in his Journal. He visited the Galapagos early in the nineteenth century, on a trip around the world.

Iguanas Pictures

Boas spend much of their time sleeping. When a boa is disturbed, it coils itself around a branch. It does not try to escape; it neither attacks nor pursues. Its only reaction is to become immobile. Those animals which seem to be aware of the power of the boa’s crushing grip may then ignore it. But the jaguar, aggressive as always, will not accept this immobility and may let fly at the reptile with a blow of a powerful paw at the snake’s most vulnerable part, the head.

Even for a snake, the equatorial forest is full of dangers and it has no assurance of leading a long and peaceful life. Perhaps that is why boas do not seem homesick in zoos. They may not have complete freedom there, but they will not encounter their enemy, the jaguar.

The Cook’s tree boa resembles the emerald boa in certain ways, especially in its habits, but it is a golden-brown colour. It hides so well among the leaves and branches of trees that it can hardly be seen. The most famous boa is probably the boa constrictor, which lives in Central and northern South America. This snake is about ten feet long. The anaconda, not only the largest boa, but thought also to be the largest snake of the New World, lives in the tropical forests of South America. It is usually found near water, either along rivers or in marshes. It eats mammals as well as birds and reptiles.

There are even two boas found in western United States. One, the rosy boa, lives in Southern California and Mexico. It is a small striped snake about three feet long. It makes its home in dry rocky areas and eats rodents. Th other boa, the rubber boa, is smaller. It also eats rodents and lizards. This brownish-grey boa lives mainly in forests of the Northwest but its range extends to California.

Emerald Tree Boa Pictures

In India, many folk tales are told about the Indian rat snake. It sometimes grows to eight feet in length and is supposed to be a welcome visitor in houses infested with rats and mice. The rat snakes of Madagascar are of great help to the sugar plantation owners because the snakes keep the rodent population under control. Otherwise the rodents would do great damage to the sugar cane crops on that island. The indigo snake, handsomer and more amiable in character than the bull snake, is also entitled to the farmer’s gratitude. If man could get used to these inoffensive creatures and overcome his repulsion, be would do justice to allies that make few demands on him.

The king snakes will attack and eat other snakes, including the poisonous rattlesnakes. The king snake almost always comes out the victor in these combats, especially if the rattlesnake is smaller. The king snake seems immune to the rattlesnake’s venom. The king snake kills its adversary by strangling it in its coils, and then eats it, starting with the victim’s head. In addition to snakes, the king snake will eat rats, small animals and birds. There are about fifteen species of king snakes found in North America.

Rainforest Snakes Pictures

The caiman stays on land during the day for hours on end, without going very far from the water—the river, lake or pond that is its hunting ground. Half-buried in the tall grass, it sleeps for hours, only getting up when it is hungry again. It gets into the water with the slow clumsy gait that is characteristic also of crocodiles and alligators. At first the caiman does not seem to be a good swimmer, but appears to be content with staying on the surface, letting the upper part of its head, the eyes and nostrils, emerge. These slow and quiet movements are only a feint. If the caiman went through the water at full speed, as it does sometimes when it has to, there would be a good chance it would not catch anything it cared to sink its teeth into; while, if it is motionless, it arouses no suspicion. Those eight feet of floating scales, with no sign of life, look remarkably like a log. Many a fish, mollusc and small amphibian continue their quiet life in the pooi with no fear whatever, until they are within reach of the huge mouth that swallows them immediately.

Then the caiman will turn again and go slowly up the bank. It has sighted a marsh bird preening its. feathers, feet out of the water. There is hardly a flutter of the bird’s wings, as the enormous animal makes its killing with incredible speed. However. things are not so easy on land for the spectacled caiman. It is up against faster animals that are very dangerous to it. There is the jaguar, for instance, who treats the reptile as it would any big lizard, and sometimes

Caiman Pictures