Giant Eland - Reproduction

Reproduction

Mating occurs throughout the year, but peaks in the wet season. Females reach sexual maturity at about two years, and males at four to five years. A female can remain in estrus for three days, and the estrous cycle is 21–26 days long. As in all antelopes, mating occurs at a time of food abundance. In some areas distinct breeding seasons exist. In southern Africa, females have been seen giving birth from August to October, and are joined by the males from late October to January. In Zambia calves are born in July and August.

Fights occur for dominance, in which the bulls lock horns and try to twist the necks of their opponents. As an act during rut, the males rub their foreheads in fresh urine or mud. They also use their horns to thresh and throw loose earth on themselves. The horns of older males get worn out due to rubbing them on tree barks. Expressions of anger are not typically observed. Dominant males may mate with multiple females. The courtship is brief, consisting of a penetration and one ejaculatory thrust.

After the courtship, the gestational period begins, which is of nine months duration. The delivery usually takes place in the night, after which the mother ingests the afterbirth. Generally one calf is delivered, and it remains with its mother for six months. Lactation can last for four to five months. After the first six months the young eland might join a group of other juveniles.

A Senegalese study focused on the suckling behaviour of giant eland and common eland calves about one to five months old determined that suckling bouts increased with the age of the calves. No other change occurred in the farmed common eland calves, but in the giant eland calves, the males were found to suckle more than female ones and shorter suckling bouts were marked in primiparous mothers than multiparous ones. The results suggest that Derby elands that lived in their natural habitat adjusted their maternal behaviour so as to be able to readily maintain a vigilant lookout for predators and other similar risks. In contrast, the farmed common elands behaved as in the conditions of captivity, without predators.