Elephant - Loxodonta africana

Genus:      Loxodonta
Species:   Africana
Kingdom:  Animalia
Phylum:    Chordata
Class:       Mammalia
Order:       Proboscidea
Family:      Eliphantidae

The mammals of the genus Loxodonta, often known collectively as Africana, are found in several regions throughout the continent, after which they are named. In recent years, elephants have received the attention of the world because of its dwindling numbers. Today there are approximately 600,000 African elephants in the world. Some believe this represents a stable population and that measures to protect them are unnecessary. Others argue that while elephants are locally overabundant in certain areas, it is impossible to ignore the fact that the overall population has dropped by a staggering amount. As recently as 1979 there were an estimated 1.3 million African elephants. Now less than one half of that population exists. This decline is attributed primarily to poaching, or illegal hunting, and habitat loss.

Evolution

Although the fossil evidence is uncertain, some scientists believe there is genetic evidence that the elephant family shares distant ancestry with the Sirenians (sea cows) and the hyraxes. In the distant past, members of the hyrax family grew to large sizes, and it seems likely that the common ancestor of all three modern families was some kind of amphibious hyracoid. One theory suggests that these animals spent most of their time under water, using their trunks like snorkels for breathing. Modern elephants have retained this ability and are known to swim in that manner for up to 6 hours and 50 km. In the past, there was a much wider variety of elephant genera, including the mammoths, stegodons and deinotheria.

Varieties

It has long been known that the African and Asian elephants are separate species. African elephantstend to be larger than the Asian species (up to 4 m high and 7500 kg) and have bigger ears. Male and female African elephants have long tusks, while male and female Asian Elephants have shorter tusks, with tusks in females being almost non-existent. African elephants have a dipped back, smooth forehead and two "fingers" at the tip of their trunks, as compared with the Asian species which have an arched back, two humps on the forehead and have only one "finger" at the tip of their trunks.

There are two populations of African elephants, Savannah and Forest, and recent genetic studies have led to a reclassification of these as separate species, the forest population now being called Loxodonta cyclotis, and the Savannah (or Bush) population termed Loxodonta africana. This reclassification has important implications for conservation, because it means where there were thought to be two small populations of a single endangered species, there may in fact be two separate species, each of which is even more severely endangered. There's also a potential danger in that if the forest elephant isn't explicitly listed as an endangered species, poachers and smugglers might thus be able to evade the law forbidding trade in endangered animals and their body parts. The Forest elephant and the Savannah elephant can hybridise successfully, though their preference for different terrains reduces the opportunities to hybridise.

Many captive African elephants are probably generic African elephants as the recognition of separate species has occurred relatively recently. Although hybrids between different animal genera are usually impossible, in 1978 at Chester Zoo, an Asian elephant cow gave birth to a hybrid calf sired by an African elephant bull (the old terms are used here as this pre-dates current classifications). The pair had mated several times, but pregnancy was believed to be impossible. "Motty", the resulting hybrid male calf, had an African elephant's cheek, ears (large with pointed lobes) and legs (longer and slimmer), but the toenail numbers, (5 front, 4 hind) and the single trunk finger of an Asian elephant. The wrinkled trunk was like an African elephant. The forehead was sloping with one dome and two smaller domes behind it. The body was African in type, but had an Asian-type centre hump and an African-type rear hump. Sadly the calf died of infection 12 days later. It is preserved as a mounted specimen at the British Natural History Museum, London. There are unconfirmed rumors of three other hybrid elephants born in zoos or circuses, all are said to have been deformed and did not survive.

Diet

Elephants are herbivores, spending 16 hours a day collecting plant food. Their diet is at least 50% grasses, supplemented with leaves, bamboo, twigs, bark, roots, and small amounts of fruits, seeds and flowers. Because elephants only digest 40% of what they eat, they have to make up for their digestive system's lack of efficiency in volume. An adult elephant can consume 300–600 lb (140–270 kg) of food a day. 60% of that food leaves the elephant's body undigested.

Social behavior

Elephants live in a very structured social order. The social lives of male and female elephants are very different. The females spend their entire lives in tightly knit family groups made up of mothers, daughters, sisters, and aunts. These groups are led by the eldest female, or matriarch. Adult males, on the other hand, live mostly solitary lives. The social circle of the female elephant does not end with the small family unit. In addition to encountering the local males that live on the fringes of one or more groups, the female's life also involves interaction with other families, clans, and subpopulations.

Most immediate family groups range from five to fifteen adults, as well as a number of immature males and females. When a group gets too big, a few of the elder daughters will break off and form their own small group. They remain very aware of which local herds are relatives and which are not. The life of the adult male is very different. As he gets older, he begins to spend more time at the edge of the herd, gradually going off on his own for hours or days at a time. Eventually, days become weeks, and somewhere around the age of fourteen, the mature male, or bull, sets out from his natal group for good. While males do live primarily solitary lives, they will occasionally form loose associations with other males. These groups are called bachelor herds. The males spend much more time than the females fighting for dominance with each other. Only the most dominant males will be permitted to breed with cycling females. The less dominant ones must wait their turn. It is usually the older bulls, forty to fifty years old, that do most of the breeding. The dominance battles between males can look very fierce, but typically they inflict very little injury. Most of the bouts are in the form of aggressive displays and bluffs. Ordinarily, the smaller, younger, and less confident animal will back off before any real damage can be done. However, during the breeding season, the battles can get extremely aggressive, and the occasional elephant is injured. During this season, known as musth, a bull will fight with almost any other male it encounters, and it will spend most of its time hovering around the female herds, trying to find a receptive mate.

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