The construction of a fence made of reinforced concrete and barbed wire threatened the existence of rare ecosystems. The European bison were one of the first to suffer and it took a lot of effort to restore their population.
The border engineering structures lead to the isolation of population groups of large mammals and depletion of their gene pool. For the European bison, as the most genetically vulnerable species, the fence will turn into a disaster.
After extinction in the wild, the bison was revived in the early 20th century from only 7 or even 5 individuals and returned to the wild. Therefore, the genetic diversity of the Belarusian bison is very low and endangered.
The integrity of the single European bison population is significantly affected by complete isolation of animals as a result of the construction of the fence in Poland. This completely eliminates the exchange of individuals between the two populations and exacerbates the low genetic diversity of the European bison of Białowieża Forest.
The largest free-living population of the European bison lives in the Bialowieza Forest: about 1400 animals (as of January 1, 2021, there were 715 bison in Poland and 675 in Belarus). On the basis of research by radio-tracking of European bison and wolf, it was found that border fences have a negative impact on the character of movement and spatial organization of wild large mammals.
Since the early 1980s, European bison have been separated by the Polish-Belarusian border fence into two separate populations. Before the construction of the fence, European bison crossed the border at a rate of 5.8 bison/1 km/year. These movements were more intense during the rutting period (August-October), when bulls roamed in search of breeding cows. For almost 30 years, the two populations remained isolated.
Many researchers estimate that minimally viable populations of large mammals must number hundreds, if not thousands, of individuals. This is especially important for such affected species as the European bison.
From the radiotracking data, it is clear that the bison movements are affected by border fencing, which has had a detrimental effect on reproduction (primarily due to the inability to exchange genetic material with the isolated Polish part of the population), dispersal and access to food resources.













