loxodonta africana

The understanding of the complex social lives of African elephants has been built up thanks to long-term studies over 20 or 30 years by dedicated field researchers, notably Cynthia Moss and colleagues in East Africa. By learning to recognise individual animals, much has been learned about social organization and the factors influencing the status and success of families and individuals.

Society
Elephant society has a structure that has been termed matriarchal. The core element is the family unit, a group of 3-25 individuals, comprising related adult females and their young. Females within the family unit are closely bonded for life. By contrast, adult males tent to be solitary, or may form temporary associations of two or three unrelated bulls. They leave the family of their birth at 12-15 years of age and, after that time, although they may frequently associate with female groups for feeding or mating, they have no long term bonds with them, or with each other.Elephants are highly intelligent animals with a complex repertoire of social interactions. Within the family group, individuals of all ages greet, and maintain bonding, by touching their trunk tips to each other’s bodies, rubbing together, and with sound communication and scent. In calves, play is a dominant behaviour. They mock charge, chase each other or wrestle with their trunks. Males, from an early age, engage in mock sparring matches. They are also more independent of their mothers than females, a trend that increases as they get older.

Female groups
Within the female groups, a few older individuals, and in particular the lead individual, termed the matriarch, are instrumental in deciding the group’s pattern of movement, in defending the group against danger, and in monitoring and responding to other approaching elephants. Calves, especially when very young, stay close to their mother, but all females in the group will aid with in their upbringing. At the approach of a predator, adult females wheel round to face the source of danger, protecting the calves that stay close behind. The members of the family unit may separate for short intervals during the day, but will soon regroup. Family units also form looser associations or “bond groups”, with more distantly related families. Occasionally, very large herds if 500 or even 1,000 elephants can be seen, primarily during migration. Even then, within the mass of animals, individual family groups maintain their integrity.

Males
There is a dominance hierarchy among bulls, generally related to their age, size, and power. If two bulls of roughly equal size meet, they assess each other through intertwining trunks, pushing and pulling, or lightly engaging their tusks. Rarely, sparring may lead to a full-scale fight, sometimes (but not always) for access to an oestrus female. The combatants will charge each other with ears outstretched, or cross tusks and attempt to twist each other off-balance, all accompanied by loud vocalisations. Each tries ultimately to gore the other with his tusks, sometimes resulting in fatal wounds by deep penetration of the head or chest. Broken tusks may result from twisting with the full body weight. The fight will end either by withdrawal of the weaker animal, or with death.Male elephants enter a periodic state called ‘musth’. The temporal gland, located on the side of the head between the ear and the eye, produces a dark fluid (temporin) with a strong musky odour. Musth males also intermittently dribble urine. A male elephant generally enters musth once a year, for a period of anything up to a month, the time of year varying with the animal. Musth bulls have heightened levels of testosterone and are very aggressive, especially toward other bulls. Musth is associated with heightened sexual activity, although non-musth bulls also mate. Females also have a temporal gland, which can occasionally be seen to ooze secretion, and elephants have been observed rubbing their cheeks against trees, so temporin may have broader communication functions. Recent research has indicated that subordinate bulls produce a different chemical signal, with a sweet aroma, which may be used to signal submissiveness to the dominant bulls and so avoid attack.

Communication
Elephants have relatively poor vision, but highly developed senses of taste and smell. They obtain chemical cues by using their trunks to touch each other’s genitals, mouths, temporal glands, and urine. They also often lift their trunks and rotate the open tips, testing the air for the scent of other animals in the vicinity. It is very likely that they can identify different individual elephants from these cues.Elephants also have acute hearing and communicate through a wide variety of vocalisations. At least 25 different calls, audible to the human ear, have been identified in African elephants, 15 of them in a low-frequency group termed rumbles. Some of them are known to be associated with different events such as musth in a bull and oestrus or copulation in a female. In addition, a range of infrasound vocalisations extends down to 5 Hz, well below the frequency of human hearing. Low-frequency sound is less subject to environmental attenuation, and elephant rumbles and infrasound are audible to other elephants over a range of up to 5 km. It has also been suggested that elephants may communicate over even longer distances as they stamp their feet on the ground, but this theory remains to be tested.

Longevity
An elephant can live to around 60 years; many die before this age, from disease, injury, starvation, drought, or predation (though the latter is rare for healthy adult animals). A remarkable aspect of elephant behaviour is their response to injured, sick and dead members of their species. Many accounts have been recorded: adult females circling around a wounded animal to prevent further attack; lifting a wounded animal to its feet and shouldering it to safety; jumping into water where a wounded animal has fallen, and heaving it out again; pulling and pushing a calf out of mud where it had become stuck; standing guard over a stricken but living animal lying on the ground; covering the body of a relative with grass and leaves as soon as it had died; returning to the carcass or even skeleton of a dead relative; and tasting, picking up, and moving the remains with their trunks.

Movement
The idea of an elephant graveyard, a place where elephants go to die, is a myth. Sick and dying elephants often go to a lakeside or river, where there is a ready supply of food and water within easy reach, and several might die in one area for that reason. In times of drought, animals congregate around water holes and many may die there.Elephants are not territorial. Although individuals or family units have home ranges, those of different animals overlap and are not defended as such. There are daily and seasonal activity patterns within the home range. They sleep lying down, usually for two to four hours in the early morning. They may also, in the hottest part of the day, stand motionless in the shade, but even when the eyes are closed, they are most likely dozing rather than sleeping.Seasonal movements, particularly in open country, may see large aggregations of hundreds of animals. In other situations, particularly in forest environments, matriarchs lead their families along the same paths that have been used for generations; these elephant trails, trampled, barren ground 1-2 m wide, can extend for tens of kilometers.Elephants walk or amble, but cannot canter or gallop. A charging animal can attain 5m per second (20 kph), while walking speed ranges from 0.5 – 2.5 m per second (2 – 10 kph). Elephants walk cautiously, appearing to place each foot with care to avoid ground that is too soft or cobbled, for example. Even so, they can manoeuvre very dense terrain and can climb up and down remarkably steep, slippery slopes. They are also adept swimmers, paddling with all four feet and using the trunk as a snorkel.

Food
Elephants consume a huge range of plant types, including grasses, herbs, shrubs, broadleaved trees, palms, and vines. Depending on the plant, they can take every conceivable part, including leaves, shoots, twigs, branches, bark, flowers, fruit, pods, roots, tubers and bulbs. The range of plants taken by an individual elephant can be anything between 100-500 species, although in a given time and place the animals may concentrate on a few species.

Seasonal
Patterns of consumption change with the seasons. In the savanna-woodland habitats of Africa, new-growth grasses are favoured in the rainy season, comprising 50-60% of the diet, but as these become tough in the dry season, the elephants switch to browse, so that the leaves and fruit of trees and shrubs now comprise 70% of the intake. For elephants in the rainforest habitats of Central Africa, the year-round supply of succulent leaves and fruits ensures that grass plays a lesser part in their diet.

Amount
Food consumption is 100-300 kg per day. Elephants spend 12-18 hours per day eating, most intensively in the morning and in the late afternoon to evening. In food-rich forest areas, elephants will typically move slowly through the day, browsing on a variety of plants, and eventually covering several kilometres. In many areas, there are daily rhythms: where both woodland and open grassland are available, for example, the elephants may spend the morning and early afternoon browsing in the woodland, emerging in the cool of the late afternoon to graze. Fluid consumption can be 200 litres of water per day in hot weather. When water is scarce, elephants will dig holes in dry stream or lake beds, using their feet, trunk, and tusks, until water seeps in and can be sucked up.

Area
When plants become ready at particular times of year, such as fruits or new shoots, elephants will gravitate towards them, using both smell and a memory from past years. Generally speaking, the poorer the quality, abundance, or predictability of food and water, the greater the distances elephants must travel to find it. Home ranges, measured by radio-collaring individuals, can be as high as 3000 km² in the Namib desert, where individuals can easily walk 80 km in a day. In many areas, migrations are seasonal. Where water is a key issue, elephants tend to accumulate in the dry season in areas where it can be found, dispersing more widely when this constraint is lifted during the wet season.

Trunk
Small items can be plucked or picked up with the terminal ‘fingers’ of the trunk; larger items, such as branches, by curling the trunk around them and pulling or twisting.  Elephants are highly inventive and can be seen, for example, kicking up sods of dry turf with their feet, picking up the resulting grassy clump with the trunk, banging it against their leg to shake off the earth, and putting it in their mouth. To reach high branches where young, succulent leaves are to be found, or high in acacia trees, where there are fewer thorns, they can rear up on their back legs, giving a total reach of up to 8 m. They will also uproot or push over trees. Finally, the trunk is important in drinking; water is not sucked all the way up into the nose like a drinking straw, but is sucked into the lower part of the trunk, then the trunk is arched and water squirted into the mouth. The only time in its life when an elephant feeds directly with its mouth is when suckling, the mouth being pressed directly against the breast with the trunk curled up out of the way.

Tusks
The tusks are used to strip bark from trees, which is then eaten; to dig for roots or for water in the dry season; and to scrape or hack salt and other minerals from the soil or exposed rock.

Teeth
The molar teeth display a series of long, thin, enamel ridges running side-by-side; for this reason, an elephant chews by swinging its lower jaw fore and aft, so that the enamel ridges on the upper and lower teeth cut past each other, shearing the food. The tremendous wear caused by feeding long hours every day on abrasive food causes the teeth to grind down to the root, and elephants not only have high-crowned teeth, but replace their teeth five times through their life, making six sets in all. Each set, however, comprises only four massive molars: lower and upper, left and right. As one tooth wears out it moves forward in the jaw and is gradually replaced by another from behind.

Digestion
The majority of an elephant’s digestion is accomplished with the aid of cellulose-digesting micro-organisms inhabiting its large intestine, especially a large blind sac opening from it, the caecum. This is a relatively inefficient method of digestion – only 40% or so of food, by weight, is utilised – but it does allow the animal to process large quantities of relatively low-nutrient food. The intestine is up to 35 m long and may weigh up to a tonne when full of food, releasing an average of 100 kg of dung per day.Elephants seem quite resistant to the tannins present in, for example, acacia bark and, by consuming a wide variety of species, they limit the intake of toxic defensive compounds specific to particular plant types. Tree bark is eaten because it provides essential minerals and fatty acids, as well as roughage. Elephants also frequent salt licks, those patches of soil or exposed rock high in minerals such as sodium.

Size
African elephants weigh 200–265 lb (90–120 kg) at birth. Unlike other mammals, they continue to grow well into adult life. Females cease growth at 25–30 years, males at 35–45.  Fully-grown savannah elephants, L. a. africana, weigh 4–7 tonnes and measure 2.5–4m high at the shoulder. The have a concave, ‘saddle-shaped’ back. Forest elephants, L. a. cyclotis, weigh 2–4 tonnes, for a shoulder height of 1.8–3 m, and have a straighter back. In comparison with the Asian species (Elephas maximus) the head is less high and is single-domed; the ears are larger, and fold back at the top; and there are two ‘fingers’ at the end of the trunk. Both sexes possess tusks, those of the female being relatively smaller, whereas in the Asian species the females generally lack tusks.

Head
The elephant’s head is proportionately very large, weighing up to half a tonne; the neck is short. The body is supported on four extremely strong pillar-like legs. The elephant has five splayed toes buried within its foot, and stands on tip-toe; the first visible joint, some distance above the ground, is not the elbow or the knee, but the wrist or ankle. The foot contains a pad of springy tissue that causes the elephant’s foot to swell sideways when it bears the animal’s weight. The tail is long, extending to below the knee, and ends in a tuft of very coarse hairs. Otherwise, the body is sparsely covered by short hair, more pronounced in very young animals. As far as is known, there are no sweat glands. The ears are very large and thin, except for a thicker supporting ridge along the top. They are richly supplied with blood vessels for heat loss, and are flapped mainly for this purpose. The skin is a uniform gray. Elephants may take on brown or other hues after wallowing in mud.

Trunk
The elephant’s trunk is, anatomically, a fusion between its nose and upper lip. The trunk is remarkably sensitive, flexible, and manoeuvrable, as well as being immensely strong. It contains no bone or cartilage, but is principally composed of muscle, in eight main sets (four on each side) comprising a total of about 150,000 separately moveable muscle units. Two nostrils run the entire length of the trunk for breathing.

Tusks
The tusks are, anatomically, greatly expanded lateral incisor teeth. They are comprised almost entirely of dentine. About a third of their length is buried within a socket in the animal’s skull. The tusks are solid, except the upper part within the socket, where there is a pulp cavity. The tusks grow by addition of dentine there, pushing them out by up to 6in (15cm) a year. The tusks of a large bull can extend 79 in (200cm) in total length and weigh 110lb (50kg) each, although such figures are rare nowadays.