24 September 2017. 
Bison bonasus

Bison belongs to a lowland line (Bison bonasus). Mature male's weight oscillates from 440 to 920 kilograms. The highest point of the withers has 1.88 meters hight. The most characteristic feature of the bull is a disproportion between the potent front and comparatively skimpy back. Cows are smaller, their weight oscillates from 320 to 640 kilograms and they have more slender front. Bison's body is covered with faded russet, perfectly blending in the surroundings fur. The front part of the animal is covered with longer hair, creating so cold beard on the lower part of the neck. Hair on the back is short. Male as well as female have on their heads high embedded horns which differ both sexes also. Mature female's horns point center much more distinct than male's. Calfs have brown-red fur when they're born and weight not much, from 16 to 35 kilograms.

Bialowieska Forest is a place where Bison bonasus managed to survive for the longest time. There were more than 700 Bisons in the forst before the World War I. Not even one of them avoided death in the war conflagration. The last one died in 1919. Years 1920-1928 are therefore the only period of time without the emperors of the Bialowieska Forest. Bisons came back in 1929 to a specially prepared game shelter. In 1939 there were 16 bisons in the forest.

After World War II Bialowieska Forest was divided with a country border. Breeding reservations with 17 Bisons that have survived were situated on the polish site. Favourable breeding developement allowed Bison to come back to nature. First two Bisons left the reservation in 1952. Their population developemet proceed intensively till 70's. In 1971 it amounted to more than 200 animals. This year was started herd abundance regulation - bisons were catched and removed to the other breeding centers.

Bisons on the polish site reached maximum population abundance in 2008 – 456 animals. It's the bigest world population of Bisons living in wild.

Bison restoration achieved a great success. However there are still several serious threats resulting of it's genetic structure, lack of suitable space to live and ways of population administration. Risk of extinction is constantly high. One of initiatives heading to more efficient Bison protection is a "Program 真br"/"Bison Programme" in which participate Mammal Reserch Center (PAN) in Bialowieza, Bialowieski National Park, National Woods Regional Board in Bialystok and Green Loungs of Poland Foundation. A main goal of the programme is to create and initiate a modern system of Bison population administration and promotion of balanced Bialowieska Forest region development based on it's natural and cultural values. In this way, Bison helps to preserve whole Bialowieska Forest.

Based on:
1. Z. Krasinski, "真br Puszcz Imperator, Bia這wieski Park Narodowy"/"Bison Forest Imperor, Bialowieski National Park", Bialowieza, 1999
2. Z. Pucek, "Historia zag豉dy i restytucji 簑br闚, Eseje o ssakach Puszczy Bia這wieskiej"/"History of extermination and restoration of Bisons, Essays on Bialowieska Forest's Mammals", Mammal Research Center (PAN), Bialowieza 2004
3. Photos: Rafal Kowalczyk