in 1958. The reserve has a maximum capacity of 13 animals but has bred around 180 animals for various zoos. As of 2020, there was also a wild breeding herd of 48 animals in Poloniny National Park with an increasing population. : Two herds in northern Spain were established in 2010. As of 2018, the total population neared a hundred animals, half of them in Castile and León, but also in Asturias, Valencia, Extremadura and the Pyrenees. : There are approximately 139 animals. : More than 50 animals. Coming from Poland, one male and four females were introduced in November 2019 into the natural reserve and forest of Suchy, Vaud Canton, western Switzerland. On 15 June 2020, the first baby of that population was born. Besides the Suchy breeding station, several zoos in Switzerland are keeping bison too. From September 2022, at least five animals will be kept in semi-freedom in Welschenrohr, with hiking paths cutting through the enclosure. : A population of around 240 animals, population is unstable and decreasing. : In 2011, 3 animals were introduced into Alladale Wilderness Reserve in Scotland. Plans to move more into the reserve were made, but the project failed due to not being "well thought through", and the project was terminated in 2013. 11 years later, 3 female bison were introduced to the West Blean and Thornden Woods in Kent, England on 18 July 2022. A calf, also female, was unexpectedly born in September 2022, bringing the total number to 4. On 24 December 2022 a bull was introduced after delays brought about by Brexit-related complications. This makes these 5 bison the first "complete" wild herd in the UK in thousands of years. Distribution The largest European bison herds — of both captive and wild populations — are still based in Poland and Belarus, the majority of which can be found in the Białowieża Forest including the most numerous population of free-living European bison in the world with most of the animals living on the Polish side of the border. Poland remains the world's breeding centre for the wisent. In the years 1945 to 2014, from the Białowieża National Park alone, 553 specimens were sent to most captive populations of the bison in Europe as well as all breeding sanctuaries for the species in Poland. Since 1983, a small reintroduced population lives in the Altai Mountains. This population suffers from inbreeding depression