Wisent: a social herd animal

Wisents live in small social groups. Cow groups consist of female animals and their offspring. The group is led by an old female. She decides on where to go and what to do: rest, ruminate, graze or drink.

If a calf is about to be born, its mother retires to a spot she has chosen in advance. When the calf is born, the mother licks it dry and helps it find her nipples. At birth the calf weighs only 30 kg. After a week the calf is strong enough to walk along with the herd and then mother and child will join the group again. The young animals grow up in the cow group, where the daughters are to stay permanently. So a cow group consists in fact of a ruling grandmother, her daughters and granddaughters and their young. At the age of 3 or 4 a cow gives birth to her first calf. If there are more calves in a group, they will rest in a nursery watched over by an older animal. From about 12 animals or more the cow group becomes too large. Then one of the older cows splits off taking her daughters and their offspring with her to form a new cow group.

Young bulls will leave during adolescence and join a bull group. At 4 they are grown up. Bulls and bull groups have home ranges which may partly overlap each other. The hierarchy among them is established by fights. Particularly during mating season the bulls look up the cow groups. Dominant bulls do not tolerate any competitors in their neighbourhood then. The strongest bulls have territories on sites where cow groups are staying. Young bulls or very old animals avoid the dominant bulls and live on home ranges hardly visited by cow groups.