Reproduction

At the start of the breeding season males establish a small territory which they defend against entry from other males. This territory is defended through calls, posturing and pushing. While most displays are ceremonial they may engage in actual fights where they lock horns. They will then mate within any females present within this territory.

Young males may be tolerated as they move through the territory as long as they exhibit submission through holding their head low.

Breeding is timed so that they females will give birth to their calf prior to the rainy season when food will be plentiful.

Females tend to give birth to a single calf each breeding season. The calf will bleat and the mother replies with a low similar to that of a domestic cow.

Within two weeks of birth the calves can move as part of the herd.

Sexual maturity is achieved by three years old for females and four years old for males.

Behavior

While some populations will remain in the same spot year round many are nomadic and will move through their habitat to find food.

Blue wildebeest form herds. Males form a bachelor herd in which they will live from one year old until three or four years old. Once males become of breeding age they no longer associate.

Males which are competing create a call which sounds like genu from which their secondary name, gnu, is derived.

Over half of the day of a wildebeest may be spent resting.

When running the blue wildebeest will reach speeds of up to 64km/h (40mph).

Predators and Threats

Natural predators of the blue wildebeest include Nile crocodiles which provide the greatest threat to this species when they attempt to cross rivers during their migration. Other threats include lions, cheetahs, hyenas and hunting dogs.

Animals in larger herds often fall prey to predators more often than those in smaller herds. This is though to be an effect of a decrease in vigilance due to a feeling of safety from the larger herd.

When a predator is sighted members of the herd will stamp and let out a loud alarm call.

As females all calve around the same time it helps the calves to survive as there are too many for the predators to hunt.

Numbers of the blue wildebeest have been reduced through the spread of humans, competition with livestock, removal of water sources and hunting for meat and for sport. The introduction of livestock has also spread disease which affects the blue wildebeest.

Fences have blocked their access to water sources causing them to pass away.

Their population is currently believed to be stable. Estimates of their population sit around 1.5 million.

Quick facts

The blue wildebeest is also known as the common wildebeest, brindled gnu or blue gnu.