An enormous herd of bison, described by scientists as the largest they have ever seen, has been spotted in the Białowieża forest in eastern Poland.
Credit: BS PAN w Białowieży
Numbering up to 170, the endangered species was picked up by drone at the end of December by researchers from the Institute of Mammal Biology monitoring bison.
A photo released by the Institute shows the herd making its way through blankets of snow and is thought to include 40 calves.
The researchers believe that the herd was formed from a combination of several smaller groups of bison which were spotted nearby at the beginning of winter.
It is thought that their congregation was the result of the sudden onset of winter which saw temperatures drop to below zero and brought heavy snowfall.
Consequently, the bison most likely groups together to increase their chances of survival.