African elephant

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African elephants

Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Proboscidea
Family: Elephantidae
Genus: Loxodonta
Anonymous, 1827
Distribution of Loxodonta africana (2007)
Distribution of Loxodonta africana (2007)
Species

Loxodonta adaurora (extinct)
Loxodonta africana
Loxodonta cyclotis

African elephants are the two species of elephants in the genus Loxodonta, one of the two existing genera in Elephantidae. Although it is commonly believed that the genus was named by Georges Cuvier in 1825, Cuvier spelled it Loxodonte. An anonymous author romanized the spelling to Loxodonta and the ICZN recognizes this as the proper authority.[1]

Fossil Loxodonta have only been found in Africa, where they developed in the middle Pliocene.

Contents

Size

Males stand 3.64 meters (12 feet) tall at the shoulder and weigh 5455 kg (12,000 lbs), while females stand 3 meters (10 feet) and weigh 3636 kg to 4545 kg (8,000 to 11,000 lbs). [2]

Teeth

Elephants have four molars; each weighs about 11 lbs and measures about 12 inches long. As the front pair wear down and drop out in pieces, the back pair shift forward and two new molars emerge in the back of the mouth. Elephants replace their teeth six times. At about 40 to 60 years of age the elephant no longer has teeth and will likely die of starvation, a common cause of death.

Their tusks are teeth; the second set of incisors become the tusks. They are used for digging for roots and stripping the bark off trees for food, for fighting each other during mating season, and for defending themselves against predators. The tusks weigh from 50-100 pounds and can be from 5 to 8 feet long. Unlike Asian elephants, both bulls and cows have tusks. [3]. The enamel plates of the molars are lesser in number than in Asian elephants.[4]

Species

Bush and Forest Elephants were formerly considered subspecies of the same species Loxodonta africana. However, they are nowadays generally considered to be two distinct species [1]. The African Forest Elephant has a longer and narrower mandible, rounder ears, a different number of toenails, straighter and downward tusks, and considerably smaller size. With regard to the number of toenails: the African Bush Elephant normally has 4 toenails on the front foot and 3 on the hind foot, the African Forest Elephant normally has 5 toenails on the front foot and 4 on the hind foot (like the Asian elephant), but hybrids between the two species commonly occur.

Conservation

Men with African elephant tusks, Dar es Salaam, c. 1900
Men with African elephant tusks, Dar es Salaam, c. 1900

Poaching significantly reduced the population of Loxodonta in certain regions during the 20th century. An example of this poaching pressure is in the eastern region of Chad—elephant herds there were substantial as recently as 1970, with an estimated population of 400,000; however, by 2006 the number had dwindled to about 10,000. The African elephant nominally has governmental protection, but poaching is still a serious issue.[5]

Human encroachment into or adjacent to natural areas where bush elephants occur has led to recent research into methods of safely driving groups of elephants away from humans, including the discovery that playback of the recorded sounds of angry honey bees are remarkably effective at prompting elephants to flee an area.[6] Some elephant communities have grown so large, in Africa, that some communities have resorted to culling large amounts to help sustain the ecosystem.[1]

Gallery

A close-up from the Addo Elephant Park, South Africa.

Bull elephants mock fighting on the rim of Ngorongoro Crater, Tanzania.

Bull elephant in the Sabi Sands of South Africa.

A breeding herd of elephants, entirely cows and young, in the Makuleke area of the Kruger Park, South Africa.

A young bull elephant in a breeding herd displaying mock aggression.

References

  1. ^ a b c d Shoshani, Jeheskel (November 16, 2005). in Wilson, D. E., and Reeder, D. M. (eds): Mammal Species of the World, 3rd edition, Johns Hopkins University Press, 91. ISBN 0-801-88221-4. 
  2. ^ <http://www.pittsburghzoo.org/wildlife_lookUpAnimal_detail.asp?categoryname=&animal=15>
  3. ^ <http://www.denverzoo.org/animals/asianElephant.asp>
  4. ^ Clutton-Brock, Juliet (1987). A Natural History of Domesticated Mammals, pp.208. ISBN 0521346975. 
  5. ^ Goudarzi, Sara (2006-08-30). 100 Slaughtered Elephants Found in Africa. LiveScience.com. Retrieved on 2006-08-31.
  6. ^ Lucy E. King, Iain Douglas-Hamilton, Fritz Vollrath (2007) African elephants run from the sound of disturbed bees. Current Biology 17: R832-R833

External links