Conservation of Endangered European Bison from the Bialowieza Forest
Denmark has recently become a new home for the European bison (also known as wisent), an endangered species that was almost wiped out in the last century. Seven animals, one male and six females, have been sent from Poland to the Baltic Sea island of Bornholm, whose environment has the same mix of deciduous trees, conifers, and meadows as the wisent’s home in Poland. The bull comes from Silesia while the six female bison come from the Polish side of the Bialowieza forest, one of the last and largest remaining parts of the immense primeval forest that once stretched across the European Plain, straddling the border between Poland and Belarus (see map). The animals were moved to the island by ferry and will remain in a 500-acre enclosure, with a plan to release them into the wild in about five years. The cost of this conservation project, funded by the Villum Foundation, is about 4 million Danish kroner, which is approximately $670,000, less than $100,000 per animal. It is hoped that this project will enable European bison numbers to grow while improving Bornholm’s biodiversity by conserving its meadows. “We want to keep grassland areas open – it’s very important for butterflies and other creatures, and the bison can keep the forest back. They love to eat the bark of young trees,” project manager Tommy Hansen told the BBC. Europe’s heaviest land mammal, the European bison (Bison bonasus) is 3 meters (10 feet) long, 2 meters (6.5 feet) tall, and weighs up to 900 kg (nearly 2000 pounds). It is thus a veritable giant compared to the roe deer, the largest mammal on Bornholm prior to the bisons’ arrival, which weighs only up to 30 kg (66 lb). It is thought that the bison will attract more tourists to the island, another welcome consequence.
Currently, European bison is considered “extremely vulnerable to extinction”. Only about 800 individuals live in the wild, mostly in the Bialowieza forest, with approximately 400 on either side of the border. But despite the growth in actual bison numbers, the genetic tests conducted by Malgorzata Tokarska of the Mammal Research Institute of the Polish Academy of Sciences have revealed that the Polish herd contains an effective population of just 25 animals. The ”effective population” measures the species’ genetic diversity, and can help predict the animal’s survival chances. Usually, a species must have an effective genetic population of 50 animals to be considered to be safe from an immediate threat of extinction caused by the dangerous effects of inbreeding or having too few alleles to adapt to new environments. The high levels of inbreeding in European bison are a result of a severe genetic bottleneck that the species went through in the early 20th century. Historically, the wisent was considered “King’s game” and as such was protected by both Polish monarchs and the Russian tsars who later conquered Poland. But in the early 20th century, the bison numbers crashed when the widespread hunger of post-World War I Europe, along with a lack of protection, led to massive poaching of the animals for meat and hide. By 1919, none were left in the wild. In the 1920s, biologists decided to reconstruct the population out of the few individuals left in the public and private collections and zoological gardens. Of the 54 European bison left in the world at the time, just four bulls and three cows went on to found the surviving pure-bred population. Of those alive today, all originate from just from just one bull, with 90% of all their genes coming from two founders. In 1952 the animal was reintroduced into the Bialowieza forest. While European bison can interbreed with American bison (Bison bison), they are generally considered to be separate species, having considerable genetic and morphological differences. Since all the European bison come from the same seven founders used to reconstruct the wild population in the 1920s, breeding methods cannot be used to enrich their genetics, says Malgorzata Tokarska: “Mostly, we can work on maintaining the bison-friendly environment and widen it”. There is some hope, however, that bringing bison together from the Polish and Belarusian herds may improve the species’ survival chances due to slight genetic differences between the two groups.
The Bialowieza forest is an important historical symbol in both Poland and Belarus. It is the subject of a famous song, “Belovezhskaya Pushcha”, composed in Russian and performed by Belarusian band Pesniary (this song video is well-worth watching for the beautiful shots of the forest and the wisent). It includes the lines:
Here is our long-forgotten family home.
And, having heard now and then the voice of ancestors calling,
Like a grey little forest bird, from far-away centuries,
I fly to you, Belovezhskaya Pushcha.
This ballad was an unofficial Soviet-time anthem of Belarus, but from 1919 to 1939 the Bialowieza forest was entirely in Polish hands. Upon the signing of the Molotov-Ribbentrop Pact, the Soviets occupied part of the forest, expelling the Polish nationals who lived there to remote areas of the Soviet Union, and in 1941 the territory was occupied by Germany, and the Soviet inhabitants were expelled. On Hermann Goering’s initiative the Bialowieza forest subsequently became a large hunting reserve for high-ranking Nazis. But the same woods also served as the hiding and fighting place for Polish and Soviet resistance fighters; graves of those who were suspected of aiding the resistance and executed by the Gestapo can still be seen in the forest. Besides the Polish and Soviet brigades, parts of the Bialowieza forest sheltered a group of Jewish partisans and non‑combatants escaped from the Zdzięcioł Ghetto and led by the four Bielski brothers. The latter became the subject of the 2008 Oscar‑winning film Defiance, starring Daniel Craig and Liev Schreiber.
The European bison, known as zubr in Polish, Russian, Belarusian, and Ukrainian, is an important cultural icon in its own right. It gave the name to Zubrowka, a brand of uniquely herb-flavored rye vodka, produced in Poland since the early 16th century. Its distinctive label features a wisent, and each bottle contains a blade of buffalo grass (Hierochloë odorata), supposedly urinated on by one of these magnificent creatures. In actuality, the wisent are fond of eating buffalo grass, hence its name. The plant is used to infuse the vodka and also gives the spirit its yellowish color. The blade traditionally placed in each bottle is largely decorative. But do not look for the original Zubrowka in the U.S.—because it contains small amounts of coumarin, which showed hepatotoxic effects in rats, importation of Zubrowka was banned in 1978 by the Bureau of Alcohol, Tobacco and Firearms. Chemists at Polmos Bialystok, the sole Polish distiller allowed to use the Zubrowka name, spent years struggling to concoct a coumarin-free version that tastes like the original, which was finally achieved in 2005. But because low-quality knockoffs without coumarin have been available in America for many years, marketing the new coumarin-free Zubrowka proved difficult and sales remain very low. One can only hope that the label of this Polish vodka will not be the only place to find the magnificent European bison in the future.