The wisent is a Eurasian species of bison. These animals were hunted to extinction in the wild in the early 20th century. Some of them were kept alive in captivity, and have since been reintroduced into several countries in Europe. They are now forest-dwelling. Wisents are the heaviest surviving wild land animals in Europe. Their coat is dense, dark to golden brown in color. They have a long mane over the forehead and underneath the neck. Both males and females have horns which are pointed forward through the plane of their faces, making them more adept at fighting.
Wisents are found in Poland, Lithuania, Belarus, Russian Federation, Ukraine, Slovakia and probably in Kyrgyzstan. These animals live in broad-leaved and coniferous forests and are often found in open grasslands.
Wisents are diurnal and social animals, which live in both mixed and only male groups. Mixed groups consist of adult females, calves, young aged 2-3 years, and young adult bulls. The average herd size is 8 to 13 animals. Herds consisting solely of bulls are smaller than mixed ones, containing 2 individuals on average. Wisents do not defend territory, and herd ranges tend to greatly overlap. Young bulls between 5-6 age usually form larger home ranges than older males. During the winter these animals often gather around feeding sites and form large mixed aggregations. Wisent herds are not family units. Different herds frequently interact, combine, and quickly split after exchanging individuals. Despite their usual slow movements, wisents are surprisingly agile. They can clear 3-m-wide streams or 2-m-high fences from a standing start.
Wisents are herbivorous animals. They feed mainly on grasses, although they also browse on shoots and leaves. In summer, an adult male can consume 32 kg of food in a day. Wisents need to drink every day, and in winter they can be seen breaking ice with their heavy hooves.
Wisents are polygynous and with the start of the rutting season, males join mixed herds with cows. The rutting season occurs from August through to October. Females usually have a gestation period of 264 days, and typically give birth to one calf at a time. Calves are born fully developed and are able to stand soon after birth. In the first days after birth, calves usually lay most of their time while their mothers are feeding with the rest of the group. At one month of age, little wisents start to forage near their mothers. They are usually weaned at around 10-12 months of age. Females become reproductive mature when they are 3 years old, while males are ready to breed at 2 years of age.
In the past, especially during the Middle Ages, wisents were commonly killed for their hide and to produce drinking horns. At present, main threats to these animals include conflict and political instability in the Caucasus, lack of habitat, fragmentation of populations, inbreeding and hybridization, disease and poaching.
According to the Wikipedia resource, the total population size of the wisent is around 6,573 individuals. There are estimates of its populations in such areas: Belarus - 1428 animals; Bulgaria - 150 animals; Caucasus - 500 animals; Czech Republic - 106 animals; France - 50 animals; Lithuania - 214 animals; Poland - 1873 animals; Romania - 100 animals; Russia - 461 animals; Ukraine - 240 animals. Currently, wisents are classified as Vulnerable (VU) on the IUCN Red List and their numbers today are increasing.