In the dry season, wildebeest (or gnus) come together in areas where there is sufficient grass and water. They used to form herds of over 100,000 animals, but due to traps being set in a number of their natural habitats, these large herds have now nearly disappeared.
The rainy season
In the rainy season, the females live in groups of around eight animals. The males tend to choose a territory that is close to water. If they don't have their own territory, they form groups of bachelors with other males.
Almost every calf is born within a three-week period. The newborn calves are easy pray for predators. Luckily predators can only eat a limited amount of meat per day. That means that there are more calves left over than there would be if their births were spread over a whole year. As the calves get a bit older, they have a better chance of escaping predators.