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.
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.
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.
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.
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.
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.
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.