Elephant is the common name for any of the large land mammals comprising the family Elephantidae in the order Proboscidea, characterized by thick skin, tusks, large pillar-like legs, large flapping ears, and a proboscis, or flexible trunk, that is a fusion of the nose and upper lip. There are only three living species (two in traditional classifications), but many other species are found in the fossil record, appearing in the Pliocene over 1.8 million years ago and having become extinct since the last ice age, which ended about 10,000 years ago. The mammoths are the best known of these.
The three living species of elephants are the African bush elephant or savanna elephant (Loxodonta africana), the African forest elephant (Loxodonta cyclotis), and the Asian elephant (Elephas maximus, also known as the Indian elephant). However, traditionally, and in some present day taxonomies, only one species of African elephant (Loxodonta africana) is recognized, with two subspecies (L. a. africana and L. a. cyclotis), and some taxonomies recognize three species of African elephant.
Elephants are the largest land animals today. Some fossil species, however, were smaller, with the smallest about the size of a large pig.
While advancing their own individual function of survival as a species, elephants also provide a larger function for the ecosystem and for humans. Ecologically, they are key animals in their environment, clearing areas for the growth of young trees, making trails, releasing sources of underground water during the dry season, and so forth. For humans, partially domesticated elephants have been used for labor and warfare for centuries and traditionally were a source of ivory. These massive exotic animals have long been a source of wonder for humans, who feature them prominently in culture and view them in zoos and wildlife parks.
However, the relationship between elephants and humans is a conflicted one, as anthropogenic factors such as hunting and habitat change have been major factors in risks to survival of elephants, the treatment in zoos and circuses has been highly criticized, and elephants have often attacked human beings when their habitats intersect.
OVERVIEW
Elephants comprise the family Elephantidae within the order Proboscidea. Proboscidea includes other elephant-like families, notably the Mammutidae, whose members are known as mastodons or mastodonts. Like members of Elephantidae, mastodons have long tusks, large pillar-like legs, and a flexible trunk or probosis. However, mastodons have molar teeth of a different structure. All proboscidians are extinct with the exception of the three extant species within Elephantidae. Altogether, paleontologists have identified about 170 fossil species that are classified as belonging to the Proboscidea, with the oldest dating from the early Paleocene epoch of the Paleogene period over 56 million years ago.
The mammoths, which comprise the genus Mammuthus, are another extinct group that overlapped in time with the mastodons. However, they also belonged to the Elephantidae family, and thus are true elephants. Unlike the generally straight tusks of modern elephants, mammoth tusks typically were curved upward, sometimes strongly curved and spirally twisted, and were long. In northern species, there also was a covering of long hair. As members of Elephantidae, they are close relatives of modern elephants and in particular the Asian elephant (Elephas maximus). They lived from the Pliocene epoch, about four million years ago to around 4,500 years ago.
Among modern-day elephants, those of the genus Loxodonta, known collectively as African elephants, are currently found in 37 countries in Africa. This genus contains two (or, arguably, three, and traditionally one) living species, with the two commonly recognized species L. africana, known as the African bush elephant, and Loxodonta cyclotis, known as the African forest elephant. On the other hand, the Asian elephant species, Elephas maximus, is the only surviving member of its genus, but can be divided into four subspecies.
African elephants are distinguished from Asian elephants in several ways, the most noticeable being their ears, which are much larger. The African elephant is typically larger than the Asian elephant and has a concave back. Both African males and females have external tusks and are usually less hairy than their Asian cousins. Typically, only the males of the Asian elephant have large external tusks, while both tusks of African elephants are large. African elephants are the largest land animals (NG).
The elephant's gestation period is 22 months, the longest of any land animal. At birth, it is common for an elephant calf to weigh 120 kilograms (260 pounds). They typically live for 50 to 70 years, but the oldest recorded elephant lived for 82 years (AC).
The largest elephant ever recorded was shot in Angola in 1956. This male weighed about 12,000 kilograms (26,000 pounds) (Sanparks), with a shoulder height of 4.2 meters (14 feet), a meter (yard) taller than the average male African elephant (SDZ 2009). The smallest elephants, about the size of a calf or a large pig, were a prehistoric species that lived on the island of Crete during the Pleistocene epoch (Bate 1907).
The elephant has appeared in cultures across the world. They are a symbol of wisdom in Asian cultures and are famed for their memory and intelligence, where they are thought to be on par with cetaceans (DC 1999), and even placed in the category of the great apes in terms of cognitive abilities for tool use and manufacture (Hart et al. 2001). Aristotle once said the elephant was "the beast which passeth all others in wit and mind" (O'Connell 2007).
Healthy adult elephants have no natural predators (Joubert 2006), although lions may take calves or weak individuals (Loveridge et al. 2006). They are, however, increasingly threatened by human intrusion and poaching. Once numbering in the millions, the African elephant population has dwindled to between 470,000 and 690,000 individuals (WWF 2009). The world population of Asian elephants, also called Indian elephants, is estimated to be around 60,000, about a tenth of the number of African elephants. More precisely, it is estimated that there are between 38,000 and 53,000 wild elephants and between 14,500 and 15,300 domesticated elephants in Asia with perhaps another 1,000 scattered around zoos in the rest of the world (EleAid). The Asian elephants' decline has possibly been more gradual than the African and caused primarily by poaching and habitat destruction by human encroachment.
While the elephant is a protected species worldwide, with restrictions in place on capture, domestic use, and trade in products such as ivory, CITES reopening of "one time" ivory stock sales, has resulted in increased poaching. Certain African nations report a decrease of their elephant populations by as much as two-thirds, and populations in certain protected areas are in danger of being eliminated (Eichenseher 2008). Since poaching has increased by as much as 45%, the actual population is unknown (Gavshon 2008).
The word "elephant" has its origins in the Greek ἐλέφας, meaning "ivory" or "elephant" (Soanes and Stevenson 2006). It also has been reported that the word elephant comes via the Latin ele and phant, meaning "huge arch" (AC).
Although the fossil evidence is uncertain, scientists ascertained through gene comparisons that the elephant family seemingly 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 (West 2001; West et al. 2003). Modern elephants have retained this ability and are known to swim in that manner for up to 6 hours and 50 kilometers (30 miles).
In the past, there was a much wider variety of elephant genera, including the mammoths, stegodons, and deinotheria. There was also a much wider variety of species.
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