Blue wildebeest are found from Kenya to eastern Namibia and down into the northern part of South Africa. Their preferred types of habitat are acacia savannahs and plains with rapidly re-growing grasses and moderate levels of soil moisture. Blue wildebeest are highly social creatures, gathering in one of the largest migratory herds among antelope species. This is caused by a seasonal shortage of suitable food and water as a result of the harsh climate within their range, and they constantly travel in search of suitable grass and water. Some individuals prefer living in the same territory throughout the year, where they gather in small social units, consisting of a single alpha male as well as up to 10 adult females with their young. Females of these groups form dominant hierarchy, which is closed for outsiders. They spend the hottest part of the day resting. Periods of increased activity are the morning and late afternoon.