By Leigh Kemp
The young of migrating animals such as the Wildebeest are able to run within half an hour of birth, enabling them to keep up with the herd. The female Wildebeest of the Serengeti also give birth within a month of each other.
With four hundred thousand young being born in such a short space of time, the affect of predation on the herd is limited. If the young were born over an extended period the predators would have more time to diminish the herd.
Non-migratory antelope use the method of hiding their young while they are feeding. A question that is often asked is whether the young are not more susceptible to predation when they are stationery. The answer is that when the young is lying down its scent glands are closed, so odour secretion is limited. The mother will move the young to a new hiding place regularly so as to prevent scent build-up.
The main danger is when a predator stumbles upon the young or if it gets up to run from perceived danger. With herding animals like Elephant and Buffalo, the young will be surrounded by the adults when danger is sensed.
Some species such as the Impala in southern Africa are known to be able to hold their birth for up to a month if conditions are not favourable. This survival technique is useful for animals that are seasonal breeders and the rains are later than usual.
There is a debate today as to whether this is possible, with some people suggesting that the late birthing is a result of late mating and not the females withholding the birth.