ELEPHANTS – Proboscidea

ELEPHANTS

ELEPHANTS FACTS

Elephants weigh 200 to 265 pounds (90 to 120 kilograms) when they are born. Even after they reach adulthood, elephants continue to grow. Females stop growing between twenty-five and thirty years and males between thirty-five and forty-five years. Adult females weigh anywhere from 3.3 to 7.7 tons (3 to 7 metric tons), depending on the species of elephant.

When compared to the size of its body, an elephant’s head is large. It weighs up to half a ton (half a metric ton) and is supported by a short neck. Elephants have four, very strong legs with feet containing five splayed, spread out, toes. The toes are buried inside the flesh of the foot so that they are invisible to the naked eye. When elephants stand, they are actually on their tip-toes, and though the first visible joint looks like a knee, it is more like a wrist or ankle. Elephant feet also have pads of tissue to help support their massive weight. The long tail ends in a cluster of coarse, rough, hair.

Elephants have no sweat glands, but their large ears contain a great number of blood vessels to assist with heat loss to help keep them cool. Their gray hide is sparingly covered with tiny, short hairs.

The tusks of an elephant are actually teeth and are covered in dentin, a material that is harder than bone. A third of each tusk is hidden inside the skull, and additional dentin forms there, pushing each tusk out at a rate of up to 6 inches (15 centimeters) yearly. The tusks of a male elephant can weight 110 pounds (50 kilograms) each and measure 79 inches (200 centimeters). If an elephant were human, its trunk would be comparable to the nose and upper lip. The trunk is extremely sensitive and flexible and contains no bone or cartilage. Instead, it is made up of about 150,000 moveable muscles, which makes it incredibly powerful. An elephant’s nostrils run the whole length of the trunk.

GEOGRAPHIC RANGE

African elephants live in central Africa, from Democratic Republic of the Congo to Mauritania. Asian elephants inhabit India, Sri Lanka, Myanmar, Indonesia, Thailand, Cambodia, Vietnam, Laos, Malaysia, Nepal, Bangladesh, and southern China.

ELEPHANTS HABITAT

Elephants live only in tropical and subtropical regions, but they occupy a wide range of habitats, including savannas (a mixture of grassland and woodland), rainforests, mountains, semi-deserts, and deciduous (trees that lose their leaves every year) forests. Elephants eat a wide variety of plants, so it is important that they live in an area that provides this essential diversity. Water is another requirement. They must live within a day’s walking distance of water in order to survive. Also of great importance is that the elephant has room to move about freely without coming into contact with humans.

Elephants have been known to change wooded area into open grassland by destroying trees.

ELEPHANTS DIET

Elephants are herbivores, plant eaters, who eat a wide range of various plant types, including grasses, trees, vines, and shrubs. They consume between one hundred and five hundred species of plants, and eat everything edible on each plant, including twigs, bark, flowers, roots, bulbs, leaves, and shoots. Tree bark is favored because it provides essential minerals and other nutrients.

What elephants eat depends on the season. During the rainy season, 50 to 60 percent of an elephant’s diet is made up of new grasses. As those grasses dry out in the African and Asian sun, the elephants eat more fruit and shrubs, which account for about 70 percent of their diet. Bamboo is a staple, basic food, for elephants residing in the forests of Asia. Elephants in the rainforests of Africa and Malaysia eat more leaves and fruits.

Elephants eat 220 to 660 pounds (100 to 300 kilograms) of food daily. Anywhere from twelve to eighteen hours of each day is spent eating. Where elephants live determines their behavior in terms of food gathering. Elephants in forest areas travel slowly, eating plants as they cover about 3 miles (5 kilometers) each day.

Elephants who live in woodlands and grasslands spend the hottest parts of the day in the wooded areas and graze in the grassland as the temperatures cool down. Elephants drink up to 53 gallons (200 liters) of water each day in hot weather. When water is hard to find, they dig holes in dried-up streams or lake beds until water seeps in, then they suck it up through their trunks.

An elephant’s trunk is a major eating utensil. Smaller items are plucked or picked up with the trunk while larger items like branches are torn away from the tree by putting the trunk around them and twisting. To reach the top of trees, elephants stand on their hind legs, which give them a total reach, combined with the stretch of the trunk, of 26 feet (8 meters). Elephants have also been observed pushing over and uprooting trees. The trunk is also important for drinking and is used like a straw. The elephant sucks water up its trunk only until it can be squirted into its mouth. Water never reaches the elephant’s nose. An elephant’s trunk can hold 2.2 gallons (8.5 liters) of water. The only time elephants eat without the use of their trunks is when they are nursing from their mothers.

Tusks are also useful for eating. They can strip bark from trees, dig for roots and water, and scrape salt and other nutrients from soil or rock. Food is chewed by grinding the lower jaw against the upper jaw, using a forward and backward motion. The molars, back teeth, of an elephant are flat-topped, each one independent from its own root. The molars are held together by a cement-like material and form blocks of enamel and dentin about 11.8 inches (30 centimeters) long. As each set wears down, another larger set moves forward to replace it. Elephants have a total of six pairs of teeth blocks, each weighing up to 8.8 pounds (4 kilograms). The final pair emerges into place around forty years of age and takes about twenty years to wear out. At that time, the elephant dies of a combination of starvation, malnutrition, and old age.

Because elephants do not digest food effectively, only about 40 percent of food by weight is used. The intestine is 115 feet (35 meters) long in comparison the human adult intestine is about 12 to 13 feet (3.7 to 4.0 meters) long. When the elephant is full the intestine weighs up to a ton (0.9 metric tons). An elephant expels an average of 220 pounds (100 kilograms) of feces daily.

BEHAVIOR AND REPRODUCTION

The female elephant, or cow, is sexually mature between the ages of twelve and fourteen and begins to reproduce shortly after that. Cows typically give birth to one calf at a time every four or five years. One of every one hundred births results in a twin delivery. The gestation period, length of pregnancy, for an elephant cow is twenty-two months. This ensures that the calf will be born during the rainy season, when grass will be plentiful for both mother and baby. Mating takes place at sixteen-week intervals year round.

Elephant cows give birth standing up, with the help of other females. Within hours, the calf will stand and take its first steps. Calves nurse, feed on their mother’s milk, until they are two or three years old, sometimes longer, depending on the timing of the mother’s next birth. Male calves nurse more frequently than do females, which becomes evident by the difference in size after the first few years.

Elephants have socially complex lives. The social structure is matriarchal (may-tree-ARK-ul), female-led, and the family is at the core. Each family unit has three to twenty-five members of adult females and their offspring. The females remain close throughout their lifetimes. Male elephants are typically solitary, preferring their own company to that of herds. They leave their birth families between the ages of twelve and fifteen and have no long-term bonds with them or any other elephants.

Groups are led by the older females, who make all decisions. Calves remain very close to their mothers, but all the females of the group will assist in raising the calves. Elephants are highly intelligent, and social interaction is complex. For example, within families, individuals greet one another by making sounds and touching each other with their trunks.

ELEPHANTS AND PEOPLE

Elephants and humans have interacted for tens of thousands of years. As long ago as thirty thousand years, people in Europe carved tools and ornaments from ivory tusks. Ivory has been used for carving because it’s hard yet has elasticity, flexibility. Elephants play an important role in Asian culture especially. Evidence points to their domestication, taming for human use, as early as the third millennium B.C.E. in India. Soon after, they were used in the military to knock down enemy buildings. Royalty used to hunt while riding on elephants’ backs. In the United States, elephants are raised in captivity in zoos and circuses.

CONSERVATION STATUS

All elephants are listed as Endangered, facing a very high risk of extinction in the wild, by the World Conservation Union (IUCN). They are threatened by habitat loss and poaching, illegal hunting, for ivory, meat, and hides.