Lifestyle and Lifespan
Elephants are the heaviest land animal and the second tallest land animal on earth. An elephant's skin is grayish-brown and may be up to one inch thick in some places on the body. The trunk has two prehensile tips. Elephants walk on their tiptoes, called digitigrade, with thick fibrous pads on their toes to cushion the bones.
The African elephant has a dip between its fore and hindquarters, giving its back a concave look. Its ears are larger than an Asian elephant's. Both sexes of African elephant have large tusks. There are two distinct species of African elephants: L. a. africana (savannah) and L. a. cyclopis (forest). The two subspecies have been evolving separately for 2.5 million years.
The majority of the skull is honeycombed with sinuses to minimize weight. Tusks are elongated second upper incisors and grow throughout the lifetime. They can grow up to seven inches a year. They are used for food gathering and carrying, defense, play, and digging. 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.
Marshes, river valleys, forests, deserts, savannas
Home range in the wild is up to 500 miles. Migratory routes are passed down by elders to offspring.
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. 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.
Elephants have no true predators except humans. Baby elephants may be preyed on by lioness but the adults will protect it most of the time. Elephants are a keystone species in their habitat. Their dung provides food and shelter to insects while also fertilizing the soil and spreading seeds. The African eggplant only grows after passing through an elephant. They dig new water sources and make existing ones bigger. They dig out caves in search of salt. By stomping out new pathways and tearing up whole trees, elephants alter their ecosystem in massive ways. This provides pathways for smaller animals, homes and food in the downed trees, and allows vegetation to grow back healthier than before. This behavior also affects humans however because elephants will destroy farms and crops in the same manner.
Most African elephants are diurnal though some herds who live near human populations have become mostly nocturnal to avoid human interactions.
Elephants have the largest brain size versus body weight other than man. 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's is 35% of adult weight. These statistics are used to distinguish instinctive from learned behavior, and are examples of higher intelligence. To cool down on hot days, elephants flap their large ears, cooling the blood in the many veins. An elephant's 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 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 8-12 years of age. Groups of related families stay in fairly close range of each other and communicate often; these are called "kin 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 everyday life. The largest males with the largest tusks, around 50 years of age, do most of the breeding, while the younger males roam. Males will stay with a female for a few weeks and then move on. Elephants communicate in many different ways. They may show submission to a more dominant individual by rubbing their eyes, swaying, lowering their head, and leveling their ears. The dominant elephant will raise their head, ears, and trunk. By snapping their ears, shaking their head, trumpeting, and rumbling elephants can also communicate with each other. Acoustic communication can happen through high and low frequency noises made with their trunk and mouth. Their large size, unique skull and cochlear structure, and trunk all allow elephants to make this wide range of calls and noises. Elephants' cochlear structure is more like a reptiles than all other mammals, which may aid in hearing low frequencies. They can also pick up seismic vibrations using their unique cochlear structure, sensitive receptors in the toes and feet, and the sensitive tip of their trunk.
Ongoing studies at Amboseli Research Center in Kenya indicate a complex bull dominance structure which determines mating success as well as everyday life. Another primary mating factor is "musth," a periodic hormonal cycle. 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' estrus cycles are roughly every 15-16 weeks with a 3 day window for conception. Males in musth will rub a female's genitals with his trunk and inhale, then exhale into his mouth. The chemicals travel to the Jacobson's organ in the roof of his mouth and he can determine if she is ready to breed. 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. Mating can happen year-round but usually coincides with the rainy season. Females will give birth every 4 to 9 years.
The calf can stand shakily and nurse (with mouth, not trunk) a few hours after birth. They are precocial, as they can see, smell, and walk after birth, though they stay with their herd for many years. Mammary glands are located between the front legs. Calves may be nursed by many different females in the herd. 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 to 45. Death comes at age 65 to 70 when the last set of teeth wear out. Elderly elephants will have sunken-in faces and turned-in ears.
African elephants are listed on Appendix I of CITES (endangered), expect for populations in Botswana, Namibia, Zimbabwe, and South Africa which are listed on Appendix II (threatened). They are considered Vulnerable by the IUCN and Threatened by the USFW.
African elephants' historical range was the area south of the Sahara. Now they are mostly confined to parks and preserves because of agricultural expansion. They are adaptable however and can survive in the bush, forest, and savannah. The biggest point in time for ivory trade was in the 18th and 19th centuries, coinciding with the slave trade and colonial expansion (Moss, et al). The CITES ban on ivory in international trade in 1989 made a huge difference but there has still been illegal hunting. The largest tusks are found on the largest males and oldest females, who respectively do most of the breeding and carry the most knowledge. The loss of these individuals in particular can have devastating effects on elephant populations. The USA passed an ivory domestic trade ban in 2016 and China will follow suit in 2017. These are currently the two biggest ivory markets.
Oakland Zoo has three partners in Africa that work with elephants. 96 Elephants is a Wildlife Conservation Society project aimed at ending the ivory trade. They estimate 96 elephants a day are lost to poaching. Big Life Foundation recruits and supports rangers to monitor elephants in a cross-border effort to end ivory poaching. The Amboseli Trust for Elephants is a project of elephant researcher, Cynthia Moss, which studies the elephants in Kenya's Amboseli National Park since 1972. In 1991, Oakland Zoo pioneered the “protected contact” methodology in animal husbandry, which places barriers between zookeepers and elephants and incorporates persuasion through rewards rather than discipline, and we continue to adhere to this practice to this day.
One of the elephant's closest living relatives is the hyrax! Found in Africa, hyraxes look like rodents but they have similar bones and teeth to elephants. Their incisions grow into long tusks and their skull structure is similar. Elephants are also related to manatees and dugongs, both marine mammals.
Elderly and dying elephants are often found near swamps. The food there is lacking in nutrition but it is softer and easily for an elephant with missing teeth to eat.
An elephants tail is 4 feet long!
University of Michigan. Animal Diversity Web. "Loxodonta africana." http://animaldiversity.org/accounts/Loxodonta_africana/
Moss, Cynthia J., Harvey Croze and Phyllis C. Lee. "The Amboseli Elephants: A long-term perspective on a long-lived mammal." Chicago: The University of Chicago Press, 2011.
Wildlife Conservation Society. 96Elephants. "Woah! China just announced..." http://96elephants.tumblr.com/post/155346289640/woah-china-just-announced-it-will-shut-down-ivory
Walker, John Frederick. "Ivory's Ghost: The White Gold of History and the Fate of Elephants." New York: Atlantic Monthly Press: 2009.
San Diego Global. "Rock Hyrax." http://animals.sandiegozoo.org/animals/rock-hyrax
Born in 1979, Donna quickly became the dominant female in our herd. Playful, she often charges into the pool for a cool-down. Donnais eager to learn, loves to participate in training, and is closely bonded with Lisa, whom she sleeps with every night.
Born in 1977, Lisa is our "water baby”, taking daily dips in the pond if the weather is right! Lisa can be sneaky and bold, grabbing treats from under another elephant’s trunk, especially Donna's. Lisa loves her sleep, after a full night and she often cat naps in the day.
Born in 1994, Osh is over 10' 8" tall and weighs 13,000 pounds and still growing! He will eventually be about twice the size of the females. elephant society, males leave their family groups in their teens. So you will often see Osh spending time on his own.