Elephant

## Impressive elephants

They’re enormous and intelligent, strong and sociable. Humans have been impressed by elephants for centuries, simply because they are so big - a male African elephant can weigh up to 7.5 tons (6.8 metric tons)! They also amaze us with their long and flexible noses, large and flapping ears, and loose, wrinkly skin. There are many stories about elephants - you've probably heard of Horton, Babar, and Dumbo. Elephants are one of the best-known animals in the world.

## African and Asian

Elephants are large and gray and have big ears and long trunks, right? If all elephants seem the same to you, take a closer look. There are two elephant species that are usually recognized: the African elephant and the Asian elephant. There is some ongoing debate about how many subspecies may exist, or whether some of these might, in fact, be species in their own right. Here are a few ways to tell them apart:

### African elephant

African elephants have large ears that are shaped like the continent of Africa, both males and females have visible tusks, their skin is very wrinkly, their back is swayed, and the end of their trunk works as if they have two fingers there to help them pick things up. African elephants are the largest mammals on land.

### Asian elephant

Asian elephants have smaller ears, usually only the males have visible tusks, their skin is not as wrinkly as African elephants’, they only have one "finger" at the ends of their trunk, and their back is dome shaped.

## Cool ears

Elephants' ears are a little like an air conditioner. As elephants flap their wet ears on a hot day, the blood flowing through the many blood vessels in the ears is cooled. This, in turn, cools their large bodies on warm days.

## Thick skin, soft heart

The term "pachyderm" is from the Greek word *pachydermos*, which means "thick skinned," and this term often refers to both elephants and hippopotamuses. An elephant's skin can be up to 1 inch (2.54 centimeters) thick on some parts of its body. It's also loose, which makes the elephant look like its wearing baggy pants or sagging stockings. But there’s a good reason for this - it keeps the animal cool by trapping moisture that takes longer to evaporate. And even though it's thick, an elephant's skin is also very sensitive to touch and sunburn. Elephants often spray themselves with water or roll in the mud or dust for protection from the sun and biting insects.

## Tooth and tusk

Tusks are an elephant's incisor teeth and are the only incisors an elephant has. They are used for defense, digging for water and food, and lifting things. The tusks present at birth are milk teeth, which fall out after a year when they are about 12 inches (5 centimeters) long. Permanent tusks extend beyond the lips at about two to three years and grow throughout the animal’s life. The tusks are composed of ivory (dentine) beneath the outer layer of enamel, but the peculiar diamond pattern of the elephant’s tusk gives it a distinctive luster that ivory tusks of other mammals such as hippos, warthogs, walruses, and sperm whales don’t have, and African elephants are sometimes killed by poachers just for their ivory tusks.

Elephants also have four molars, one on the top and one on the bottom on both sides of the mouth. One molar can weigh about 5 pounds (2.3 kilograms) and is the size of a brick! Each elephant can go through up to six sets of molars in its lifetime. New teeth do not erupt vertically, as in most mammals, but grow in from behind, pushing the old worn-out teeth forward and out, like a production line of teeth moving along the jaw from back to front. When elephants get old, their remaining molars are sensitive and worn down, so they prefer to eat softer food. Marshes are the perfect place for soft plant food, so old elephants are often found there. Many times, they stay there until they die. This practice led some people to think that elephants went to special burial grounds to die.

## A unique nose

An elephant's trunk is both an upper lip and a nose. There are 8 major muscles on each side of the trunk and 150,000 muscle fascicles (portions of muscles) for the entire trunk. There are no bones or cartilage in this unique appendage. An elephant's trunk is so strong it can push down trees and so agile that it can pick up a single piece of straw. Elephants also use their trunk like we use our hands: to grab, hold, pick up, reach, touch, pull, push, and throw.

The trunk is still a nose, too, and has two nostrils at the end that suck air up the long nasal passages and into the lungs. Elephants also use their trunks to drink, but the water doesn’t go all the way up the nose like a straw; instead, the elephant sucks water only part way up the trunk, curls it toward its mouth, tilts its head up, and lets the water from the trunk pour in.

## The biggest of all

The largest elephant on record was an adult male African elephant. He weighed about 24,000 pounds (10,886 kilograms) and was 13 feet (3.96 meters) tall at the shoulder! Most elephants don't get that large, but African bush elephants do grow larger than Asian elephants.

## A huge habitat

Asian elephants live in India, Nepal, and parts of Southeast Asia. Their habitat is scrub forest and rain forest, and they are often found along rivers during dry months.

African bush elephants are found in eastern, central and southern Africa, living in lowland and montane forests, flood plains, and all types of woodland and savanna. The smaller African forest elephants inhabit the Congo basin and western Africa in moist, semi-deciduous rain forests.

## Big appetites

Elephants eat all types of vegetation, from grass and fruit to leaves and bark - about 165 to 330 pounds (75 to 150 kilograms) each day, which is about 4 to 6 percent of their body weight. They spend an average of 16 hours per day eating! Bush elephants are grazer-browsers and eat grasses, including sedges, flowering plants, leaves, shrubs, and small to medium-size trees. Forest elephants are browser-frugivores and eat leaves, fruits, seeds, branches, and bark. Asian elephants are both browsers (feeding on shrubs and trees during the dry season and after heavy rains) and grazers (feeding on grass during the first part of the wet season). They can consume many species of plants, as well as twigs and bark. The choice of plants varies with seasons.

The elephants at the San Diego Zoo and the San Diego Zoo Safari Park eat less than their wild counterparts - about 125 pounds (57 kilograms) of food each day - because they don’t have to burn as many calories looking for food. Still, the adult male African elephants at the Safari Park need to eat over 70,000 calories each day! Our elephants are offered hay, herbivore pellets, and acacia browse daily. Elephants drink 20 to 50 gallons (75 to 190 liters) of water each day.

## Life in a herd

All elephants live in close social groups called herds, usually made up of related females and their offspring. The leader of the herd is known as the matriarch; she is usually the oldest and most experienced female in the group. The matriarch remembers where and how to find food and water, how to avoid predators, and the best places for shelter. She also keeps the younger elephants in line and teaches them how to behave in elephant society. In some cases, the group may include one of the matriarch’s sisters and her offspring. When groups get too big, “bond groups” split off but maintain a loose association.

Adult males don't usually live in a herd. Once male elephants are old enough to find their own food and protect themselves, they leave the herd and live on their own or form bachelor herds with other males. Only after they become adults do they visit herds of females, and that is only for short periods of time to breed. Bulls do not take part in caring for the young.

Etiquette is important in elephant society. Trunks are used in greeting: a lower-ranking animal will insert its trunk tip into the other’s mouth. A trunk may be held out to an approaching elephant as a greeting and is also used in caressing, twining, wrestling, and checking reproductive status.

## Catch me if you can!

Which animals would want to attack an elephant? Not many! Elephant calves could be a potential meal for hyenas, lions, leopards, or crocodiles, but as long as they stay near Mom or their herd, they have little to worry about. If an elephant senses danger, it trumpets a loud alarm call to alert the others. The herd then forms a protective ring, with youngsters in the middle and the adults facing out to confront a potential predator. A healthy adult elephant’s only foe is a human poacher with a powerful rifle.

## Sound off!

Elephants make many different sounds; humans cannot hear some of these sounds, as their frequency is too low for our ears. Elephants use these sounds to communicate with each other over long distances. Have you ever had your stomach growl at an unfortunate moment? Well, stomach growls are a welcome sound in elephant society; a stomach that makes loud rumbling and growling noises seems to signal to others that everything is "okay."

## Baby elephant walk

At birth, a baby elephant, called a calf, may stand three feet (one meter) tall. A calf is usually quite hairy, with a long tail and a very short trunk, and is very dependent upon its mother and other members of the herd. The little one uses its mouth to drink its mother's milk, so it doesn't need a long trunk to feed. Calves stick close to Mom and nurse frequently; they gain on average, 2 to 3 pounds (1 to 1.3 kilograms) a day in their first year! Herd mates tend to look out for the calves if they are in distress.

Despite all the playtime and protection, calves still have to navigate through social nuances and establish their social rank within the herd. Babies spend their days practicing making all four legs go in the same direction at the same time, perfecting their ear flaring, and mastering trunk control. Calves are clumsy at first with their trunk, but they learn to use it as they grow older. By the time they are two to three years old, they no longer need to nurse.

## Appreciating elephants

The more we learn, the more we appreciate the complexity of elephants. Being close to a living, snorting, rumbling elephant is a powerful experience. We think it’s one that can also inspire current and future generations to help conserve Nature’s magnificent masterpieces.