African Bush Elephant

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{{Taxobox | color = pink | name = African Bush Elephant | status = en | image = African Elephant in Kenya.jpg | image_width = 250px | regnum = Animalia | phylum = Chordata | classis = Mammalia | ordo = Proboscidea | familia = Elephantidae | genus = Loxodonta | species = L. africana | binomial = Loxodonta africana | binomial_authority = (Blumenbach, 1797) }} The African Bush Elephant (Loxodonta africana) is the better-known and larger of the two species of African elephants. Both it and the African Forest Elephant were previously classified as a single species, known simply as the African Elephant. It is also known as the Bush Elephant or Savanna Elephant.

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Description

The African Bush Elephant is a large animal that normally reaches 6 to 7.3 m (20 to 24 ft) in length and 3 to 3.5 meters in height, although a 4-meter elephant, the body of which is mounted in the rotunda of the National Museum of Natural History in Washington, D.C., was discovered in Angola in 1955. Weighing between 7,000 and 10,000 kg (22,000 lb), it is the largest land animal in the world. It moves at a rate of 6 km/h, but it can reach a top speed of 40 km/h when scared or upset.

The animal is characterized by its large head; two large ears that cover its shoulders and radiate excess heat; a large and muscular trunk; two prominent "tusks" (incisors), which are well-developed in both sexes, although more commonly in males; a short, almost nonexistent neck; a large, barrel-like body; four long and heavy legs that resemble columns; and a relatively short tail.

The animal is protected by a heavy but flexible layer of gray-brown skin, dotted with mostly undeveloped patches of hair and long, black hair at the tip of its tail. Its back feet have three toes that form a hoof, while the number of toes on the front feet have varied between four and five, in different instances. The front is smoother and less convex than that of the Asian Elephant.

The trunk is the most characteristic feature of the African Bush Elephant. It is formed by the fusion and elongation of the nose and upper lip, forming a flexible and strong organ made purely of muscle.

Relatively little scientific research has been carried out into elephants' cognitive or perceptual abilities. An exception is a recent report that African elephants are able to use seismic vibrations at infrasound frequencies for communication (Günther et. al, 2004).

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Diet

Image:Elephant grasping thorn tree by mexikids.jpg African elephants are herbivorous. The diet of the African Bush Elephant varies according to its habitat; elephants living in forests, partial deserts, and grasslands all eat different proportions of herbs and tree or shubbery leaves. In order to break down the plants they consume, the African Bush Elephant has four large molars, two in each mandible of the jaw. Each of these molars is 10 cm wide and 30 cm long. Over time, these molars are worn away and new ones are grown to replace them as the elephant ages. Around the age of 15 their milk teeth are replaced by new ones that last until the age of 30, and then by another set which wear off past the age of 40, being replaced by the last set of teeth that last approximately until the age of 65–70. Not much later, the animal dies of starvation from not being able to feed correctly. There are known cases of over 80 year old specimens in captivity.

These animals are considered quite 'wasteful', as it is normal that they ingest an average of 225 kg of vegetal matter that is defecated without being totally digested. That, combined with the long distances that they can cover daily in search of more food, contributes notably to the dispersion of many plant seeds that germinate in the middle of a nutrient-filled feces mound. In their feeding-oriented whereabouts, elephants rip apart all kind of plants, and knock down trees with the tusks if they are not able to reach the tree leaves not even standing up straight, as actual living bulldozers. It can be said that they carry devastation with them. That causes deep trouble for other species and to the elephants themselves in national parks where there is overpopulation, so that managers of overpopulated parks often contact other parks with fewer specimens to transfer excess individuals.

Elephants also drink great quantities of water, over 190 liters per day.

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Social behaviour

Image:Afrikanische Elefanten (Loxodonta africana).jpg The African Bush Elephant is a notably inteligent animal. In fact, experiments about reasoning and learning applied on them show that they are the smartest ungulates together with their asian cousins. This is mostly due to their large brain.

Packs are made up of related females and their younglings of assorted ages, directed by the eldest female, called the matriarch. Infrequently, an adult male goes with them, but those usually leave the pack when reaching adolescence to form packs with other elephants of the same age. Later, they spread out, carrying out a lonely life, approaching the female packs only during the mating season. Nevertheless, elephants don't get too far from their families and recognise them when re-encountered. Sometimes, several female packs can blend for a period of time, reaching even hundreds of individuals.

The matriarch is the one who decides the route and shows to each other member of the pack all the water sources she knows, which the rest will memorize in the future. The relations among the members of the pack is very tight; when a female gives birth to a baby the rest go to aknowledge it touching her with the trunk; and when an old elephant dies the rest of the pack will stay by the corpse for a while. The famous Elephant Graveyards are a myth, but it is true that these animals can recognise a carcass of its species when they find one during their trips, and even if it is a stranger, they form around it and sometimes they even touch its forehead with their trunk.

Mating happens when the female feels ready, an event that can occur anytime during the year. When she is ready, she starts emitting infrasounds that attract the males, sometimes many kilometers away. The adult males start arriving to the pack during the following days and begin fighting head-to-head between them, causing some injuries and even broken tusks. The female shows her acceptance of the victor by rubbing her body against his. They mate, and then both go their own way. After 22 months of gestation (the longest among mammals), the female gives birth to a single 90cm-high calf which weighs more than 100 kg. The baby feeds on the mothers milk until the age of 5, but also eats solid food from as early as 6 months old. Just a few days after birth the calf can follow the pack by foot, and so the pack resumes its course.

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Predators

The adult African Bush Elephant lacks natural predators thanks to its great size, but the calves (especially the newborn) are vulnerable to lion, leopard, crocodile, and, more rarely, hyena attacks. Adult females of a group will attack approaching predators. Predation, as well as drought, contribute significantly to infant mortality. The African Bush Elephant shows a special aversion towards rhinoceroses, to the point that elephants will attack them on sight. This behaviour is mostly observed with male elephants, especially the younger ones, and there have been cases of adolescent elephants who seem to enjoy this kind of fight.

Humans are the elephant's major predator. Elephants have been hunted for meat as well as the rest of the body, including skin, bones, and tusks. Elephant trophy-hunting increased in the 19th and 20th centuries, when tourism and plantations increasingly attracted sport hunters. In 1989, hunting of the African elephant and ivory trading were forbidden, after the elephant population fell from several million at the beginning of the 20th century to fewer than 700,000. The population of African elephants was halved during the 1980s. Scientists then estimated that, if no protective measures were taken, the wild elephant would be extinct by 1995. The protection that the elephant now receives has been partially successful, but despite increasingly severe penalties imposed by governments against illegal hunting, poaching is still common. CITES still considers this species as threatened with extinction.

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Species differences

The African elephant genus Loxodonta is composed of two species, the African Bush Elephant (Loxodonta africana) and the African Forest Elephant (Loxodonta cyclotis). The African Forest Elephant has a longer and narrower mandible, rounder ears, a different number of toenails, different tusks, and considerably smaller size.

Another possible species (or subspecies) existed, but it has not been recognised yet as it by the scientific community: The North African Elephant (Loxodonta pharaonensis), also known as Carthaginian Elephant or Atlas Elephant. This species, extinct nowadays, lived between the Magreb and the Nile mouth, and had a smaller size than the Savanna Elephant, probably similar to the Forest Elephant. It is also possible that it was more docile that the Savanna Elephant, letting the Carthaginians tame it with an unknown method. To this species belonged the elephants with whom Hannibal crossed the Pyrenees and the Alps in order to invade Italy during the Second Punic War. These elephants were also trained and used by the Ptolemies of Egypt. The historian Polybius (Histories 5.83) describes their inferiority in battle against the larger Indian elephants used by the Seleucid kings. A remaining Ptolemaic inscription does in fact speak about three types of war elephants, the Troglodytic (probably Libyan) and Ethiopian, as well as Indian. The Ptolemaic king prides himself with being the first to tame the Ethiopian elephants, a stock which should be identic to one of the two extant African species.

After the conquest of Sicily, the Romans seemed to gain interest in capturing some specimens that have been left behind in the middle of the island, but failed eventually. The species must have become extinct some decades after the roman conquest of North Africa.

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References

da:Afrikansk savanneelefant de:Afrikanischer Elefant es:Loxodonta africana he:פיל אפריקני lb:Afrikaneschen Elefant lt:Afrikinis dramblys li:Savanneolifant nl:Savanneolifant pl:Słoń afrykański sk:Slon africký fi:Savanninorsu sv:Afrikansk elefant

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