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African Bush Elephant (Loxodonta africana) - Wiki
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African Bush Elephant
From Wikipedia, the free encyclopedia
[Photo] African elephant in Kenya. ?? Sam Stearman, 2004. http://www.samsays.com/
The African Bush Elephant (Loxodonta africana) is the 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.
Description
The African Bush Elephant is the largest land dwelling animal, normally reaching 6 to 7.3 meters (19.7 to 24.0 feet) in length and 3 to 3.5 meters (9.8 to 11.5 feet) in height, and weighing between 7,000 and 10,000 kg (15,000-22,000 lb.
The largest on record, shot in Angola in 1955, was a bull weighing 12,274 kg (27,000 lb) and standing 4.2 meters (13.8 feet) high, the body of which is now mounted in the rotunda of the National Museum of Natural History in Washington, D.C.. The Bush Elephant normally moves at a rate of 6 km/h (4 mph), but it can reach a top speed of 40 km/h (25 mph) 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, which are well-developed in both sexes, although more commonly in males; a short neck; a large, barrel-like body; four long and heavy legs; 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. 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.
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.[3]
Diet
African elephants are herbivorous. Their diet varies according to their habitat; elephants living in forests, partial deserts, and grasslands all eat different proportions of herbs and tree or shrubbery 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 typically ingest an average of 225 kg of vegetal matter daily, which is defecated without being fully 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. Elephants rip apart all kind of plants, and knock down trees with the tusks if they are not able to reach the tree leaves. In some national parks 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.
Social behaviour
The African Bush Elephant is an intelligent animal. Experiments with reasoning and learning show that they are the smartest ungulates together with their Asian cousins. This is mostly due to their large brain.
Herds are made up of related females and their young, 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 herds with other elephants of the same age. Later, they spread out, carrying out a lonely life, approaching the female herds only during the mating season. Nevertheless, elephants do not get too far from their families and recognise them when re-encountered. Sometimes, several female herds 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 herd all the water sources she knows, which the rest will memorize in the future. The relations among the members of the herd is very tight; when a female gives birth to a baby the rest go to acknowledge it touching her with the trunk; and when an old elephant dies the rest of the herd 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 from kilometers away. The adult males start arriving at the herd during the following days and begin fighting, 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 90 cm 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 herd by foot.
Some African Bush Elephants will attack and kill rhinoceroses. This behaviour, when it occurs, is mostly observed with younger adult male elephants who have come into musth prematurely.
Predators
In most places, the adult African Bush Elephant lacks natural predators thanks to its great size, but the calves (especially the newborn) are vulnerable to lion and crocodile attacks, as well as the rare leopard and hyena attacks. However, the lions of the Tsuave have learned to kill even adult elephants. Predation, as well as drought, contribute significantly to infant mortality.
Humans are the elephant's major predator. Elephants have been hunted for meat, 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.
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 than the Savanna Elephant, letting the Carthaginians tame it with an unknown method. The elephants with whom Hannibal crossed the Pyrenees and the Alps in order to invade Italy during the Second Punic War belonged to this species.
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 identical to one of the two extant African species.
After the conquest of Sicily, the Romans wanted to capture some specimens that have been left behind in the middle of the island, but failed. The species must have become extinct some decades after the Roman conquest of North Africa.
Conservation
While the species is designated as vulnerable, conditions vary somewhat by region within eastern and southern Africa. For example, The 2006 Zakouma elephant slaughter in southeastern Chad refers to a series of poaching massacres of African elephants in the vicinity of Zakouma National Park. These killings have been documented in aerial surveys conducted from May through August of 2006 and total at least 100 animals.[4] This region has a four decade history of illegal killing of this species; in fact, the Chad population was over 300,000 animals as recently as 1970 and has been reduced to approximately 10,000 as of 2006. The African elephant nominally has Chadian governmental protection, but the implementation practices of the government (backed with EU help) has been insufficient to stem the slaughter by poachers.[5]
http://en.wikipedia.org/wiki/African_Bush_Elephant
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| The African bush elephant (Loxodonta africana) is the larger of the two species of African elephant. Both it and the African forest elephant have in the past been classified as a single species, known simply as the African elephant. |
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