Elephant


ORDER: Proboscidea

FAMILY: Elephantidae

GENUS: Loxodonta

SPECIES: africana

DESCRIPTION:
The adult male is much larger than the adult female. Head and body length including trunk: 19-24 feet. Shoulder height: 10-13 feet. Weight: 5.5 -7 tons. Tail: 4 feet. Brownish gray skin has folds and may be one inch thick in places. The African Elephant has a marked dip between its fore and hindquarters giving a concave curvature to its back. Ears are large and fan-like. The trunk has two prehensile protrusions at the tip. Large tusks are present in both sexes. Elephants are digitigrade with pads of fibrous tissue to cushion toe bones. Oakland Zoo also supports several elephant conservation programs: Save the Elephants, Amboseli Trust for Elephants, The Elephant Sanctuary, PAWS, and Namibia Seismic Communication.

GEOGRAPHICAL RANGE AND HABITAT:
Natural home range is 500 miles; migratory patterns are taught from one generation to the next. Now they are mostly restricted to parks and preserves. Habitat formerly was area south of the Sahara; agricultural expansion has severely reduced it. Highly adaptable, elephants can survive in forest, bush or savannah.

DIET:
Elephants have an inefficient digestive system and digest only about 40 percent of what they eat. They eat enormously. Estimates in the wild range from 100-1000 pounds of vegetation per day (a 16 hour period). Zoo elephants are estimated to eat approximately 50 pounds of food per ton of elephant per day. Working elephants need 300 to 600 pounds of food per day. The wild elephant is a destructive eater, uprooting and scattering as much as is eaten, often breaking down whole trees. Elephants eat almost anything green, but green grass, shoots and buds of trees and shrubs are preferred. Farms are often raided for fruits and vegetables of all types. Average daily consumption of water for full-grown animals is between 30 and 50 gallons.

LIFE CYCLE/SOCIAL STRUCTURE:
Elephants live in a complex matriarchal society normally composed of 8 to 15 related members and led by a dominant cow. Three or four generations of cows and calves spend their entire lives together with the exception of males, who leave the group at puberty. Groups of related families stay in fairly close range of each other and communicate often; these are called in groups In times of danger, kin groups will mass and form clans of 200 or more. Ongoing studies at Amboseli Research Center in Kenya indicate a complex bull dominance structure which determines mating success as well as every day life. Another primary mating factor is &dquo;musth&dquo; a periodic hormonal cycle seen in both species. Physical manifestations in males include heavy secretions from temporal glands, high blood testosterone levels, urine dribbling (marking) and aggression. Cows seem to prefer a musth bull, but can successfully breed whether the bull is in musth or not. According to keepers, our cows oestrus cycles are roughly 15-16 week ones and last 3 days. Gestation is approximately 22 months. The birth is usually a single one; twins are born only 1.35% of the time. Birth weight is 175 to 250 pounds. The mother is often assisted by another cow during birthing. The calf can stand shakily and nurse (with mouth, not trunk) a few hours after birth. Mammary glands are located between the front legs. Although calves usually start eating other food in their first year and could survive if weaned at two and a half years of age, they will nurse until the birth of the next calf (usually 4-5 years) and are very dependent on their mothers for eight to ten years. Adolescence occurs at 12 to 14 years of age. Most physical growth is reached at 20, but growth continues throughout life. Top mental ability is at age 30 to45. Death comes at age 65 to 70 when the last set of teeth wear out.

SPECIAL ADAPTATIONS:
The majority of the skull is honeycombed with sinuses to minimize weight. Tusks are elongated second upper incisors and grow throughout the lifetime. They are used for food gathering and carrying, as well as weapons. Molars make up other dental equipment; six consecutive sets of two upper and two lower molars are produced throughout life. The first set has three enamel layers, increasing to ten layers in the sixth set. The trunk is an elongation of the nose and upper lip; in adults it contains 150,000 muscles. It is used for eating, drinking, dust and water bathing, as well as communication. The sense of smell is highly sophisticated; they are believed to locate underground water by smelling the earth above. Vision is poor. Long lashes and nictitating lids protect the eyes from dust. Hearing is acute. Recent studies establish the use of infrasound (tones lower than humans can hear) for long-range communication. Ears are also used to control body temperature; blood circulating through the large vessels in the ears is cooled by flapping.

INTERPRETIVE INFORMATION:
Skin is extremely sensitive to sunburn and insect bites; they roll in dust and mud and throw dust on their backs to help protect their skin. Elephants have the largest brain size versus body weight other than man. New intelligence data: most mammals, excluding primates, are born with a brain weight of 90% of adult weight. A human brain at birth is 26% of adult weight, and the elephant is 35% of adult weight. These statistics are used to distinguish instinctive from learned behavior, and are examples of higher intelligence.

OUR ANIMALS:
1 Male, 3 Females. Our male elephant (born in 1994) came here from England in 2004. The oldest female elephant (born around 1969) came from the San Diego Zoo in 1993. The second oldest elephant (born around 1977) came here in 1979 when she was only 2. Our youngest female elephant (born around 1980) came here from the New Orleans Zoo when she was 10.

STATUS IN WILD:
Endangered due to loss of habitat and poaching for ivory. They are listed on Appendix II of CITES (threatened), as Endangered by the IUCN and Threatened by the USFW.

BIBLIOGRAPHY:

  1. Grzimek, Bernhard. 1972. Animal Life Encyclopedia, Van Nostrand Reinhold, New York.
  2. Douglas-Hamilton, 1975. Among the Elephants.
  3. Moss, Cynthia. 1988. Elephant Memories. Wm. Morrow & Co, New York.
  4. Moss, Cynthia. 1982. Portraits in the Wild. University of Chicago Press.
  5. Nowak, Ronald. 1991. Walker Mammals of the World, 5th Ed. Vol II. Johns Hopkins University Press.
  6. Zoobooks (Elephants), 1986.

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