Social Spacing:

Because of the elephants large size, it must consume large quantities of food each day to survive. Most large animals, like the elephant and gorilla feed primarily on vegetable matter due to the increased energy availability in these primary producers (Drickamer and Vessey, 1986). When browsing or grazing in forests or savannas, it is not easy to find enough food to support an elephant in a small space. Thus the elephants must stay mobile to ensure a constant supply of food. Furthermore, the lack of water during the dry season forces the elephant to move in search of fresh water sources. For these reasons, an elephant could not feasibly defend a territory large enough to support itself and its offspring. Thus, because food sources are not plentiful, predictable, and evenly distributed, elephants have home ranges. These home ranges vary in size dependent upon the needs of the elephants. Cows (female elephants) with offspring may have home ranges as small as 15-50 km² - allowing for the slow pace of the offspring's movement and the increased feeding needs of the nursing mother (Beck and Ornstein, 1991). On the other end of the spectrum, bulls (male elephants), who spend a great deal of the wet season searching for mates, may have home ranges that extend to 500-1,500 km² (Beck and Ornstein, 1991). These home ranges may overlap with the home ranges of other elephants. This is another possible explanation for why the male elephants' home ranges are so much larger than the females. To improve their chances of mating, it is important for the bulls to encounter as many females as possible. The more females they encounter, the greater the chance that they encounter a female in estrous. The more females in estrous they mate with, the greater the chance that they will produce offspring. The more offspring they produce, the more successful they are in terms of natural selection. Although their groups are usually relatively small, when stressed, especially by human attacks, multiple groups of elephants may group together into large herds (Sikes, 1971).

Due to migration, feeding, and the search for mates, much of the elephants time is spent awake, in fact, they can seldom be caught sleeping. At night the African elephant takes between one and three hours of sleep. Contrary to what was previously believed, during this period of rest the elephant is often lying down - catnaps during the day, however, may be taken standing up (Alexander, 2000).

Cows, who have the responsibility of raising the offspring, live in kin groups composed of sisters, aunts, mothers, and various offspring. In these kin groups, they are led by the matriarch - typically the oldest female cow in the group. The group will eat and migrate at her command. Kinship groups (kin groups) have been witnessed to grow to as many as 50 or more individuals (Douglas-Hamilton, 1975). At times, groups of loosely related kin groups may come together to form aggregations of as many as 100 elephants including several attending bulls (Douglas-Hamilton, 1975). When a likely predator approaches, a kinship group will crowd together between the predator and the juvenile elephants in the group (Sikes, 1971). Because the cows in the kinship group are all related, it is to their advantage to aid in the protection of one another's offspring. Such efforts increase each individual cows inclusive fitness.

As elephants grow older, they can sometimes be seen to 'retire' in their old age. They will inhabit an area with a plentiful water source, such as a lake, river, or swamp, which contains plenty of soft, moist vegetation (Sikes, 1971). This is presumably because these softer food sources do less damage to the teeth of the aging elephant. Furthermore, it seems that the strains of migrating in search of healthy, receptive females may be better rewarded during the wet season when food is plentiful and females tend to be more receptive (Barnes, 1982). Thus the older elephants maximize their life expectancies while remaining somewhat sexually active.

Onward to Mating System!