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Elephant fact file
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The African elephant and the Asian elephant are the only two surviving species of what was in prehistoric times a diverse and populous group of large mammals. Fossil records suggest that the elephant has some unlikely distant relatives, namely the small, rodentlike hyrax and the ungainly aquatic dugong. They all are thought to have evolved from a common stock related to ungulates. In East Africa many well-preserved fossil remains of earlier elephants have aided scientists in dating the archaeological sites of prehistoric man. Physical charastics The tusks, another remarkable feature, are greatly elongated incisors (elephants have no canine teeth); about one-third of their total length lies hidden inside the skull. The largest tusk ever recorded weighed 214 pounds and was 138 inches long. Tusks of this size are not found on elephants in Africa today, as over the years hunters and poachers have taken animals with the largest tusks. Because tusk size is an inherited characteristic, it is rare to find one now that would weigh more than 100 pounds. Both male and female African elephants have tusks, although only males in the Asiatic species have them. Tusks grow for most of an elephant’s lifetime and are an indicator of age. Elephants are “right- or left-tusked,” using the favored tusk more often as a tool, thus, shortening it from constant wear. Tusks will differ in size, shape and direction; researchers use them (and the elephant’s ears) to identify individuals. Although the elephant’s remaining teeth do not attract the ivory poacher, they are nonetheless interesting and ultimately determine the natural life span of the elephant. The cheek teeth erupt in sequence from front to rear (12 on each side, six upper and six lower), but with only a single tooth or one and a part of another, being functional in each half of each jaw at one time. As a tooth becomes badly worn, it is pushed out and replaced by the next tooth growing behind. These large, oblong teeth have a series of cross ridges across the surface. The last molar, which erupts at about 25 years, has the greatest number of ridges but must also serve the elephant for the rest of its life. When it has worn down, the elephant can no longer chew food properly; malnutrition sets in, hastening the elephant’s death, usually between 60 and 70 years of age. The African elephant’s ears are over twice as large as the Asian elephant’s and have a different shape, often described as similar to a map of Africa. The nicks, tears and scars as well as different vein patterns on the ears help distinguish between individuals. Elephants use their ears to display, signal or warn when alarmed or angry, they spread the ears, bringing them forward and fully extending them. The ears also control body temperature. By flapping the ears on hot days, the blood circulates in the ear’s numerous veins; the blood returns to the head and body about 9 F cooler. Habitat Behaviour Females mature at about 11 years and stay in the group, while the males, which mature between 12 and 15, are usually expelled from the maternal herd. Even though these young males are sexually mature, they do not breed until they are in their mid- or late 20s (or even older) and have moved up in the social hierarchy. Mature male elephants in peak condition experience an annual period of heightened sexual and aggressive activity called musth. During this period, which may last a week or even up to three to four months, the male produces secretions from swollen temporal glands, continuously dribbles a trail of strong-smelling urine and makes frequent mating calls. Females are attracted to these males and prefer to mate with them rather than with males not in musth. Smell is the most highly developed sense, but sound deep growling or rumbling noises is the principle means of communication. Some researchers think that each individual has its signature growl by which it can be distinguished. Sometimes elephants communicate with an ear-splitting blast when in danger or alarmed, causing others to form a protective circle around the younger members of the family group. Elephants make low-frequency calls, many of which, though loud, are too low for humans to hear. These sounds allow elephants to communicate with one another at distances of five or six miles. Diet Caring for the young Predators |