A genetic study of brown bears (Ursus arctos) in Bulgarian mountain regions showed they originated in Carpathia. So how did they get to Bulgaria? It wasn't natural dispersal. 

Bulgarian and Romanian NGOs, the Frankfurt Zoological Society, and scientists of the Senckenberg Conservation Genetics Section in Frankfurt have found that a legend was probably true - the legend being that the former leader of the Romanian Communist Party, Nicolae Ceausescu, flew the bears to Bulgaria.

The brown bear (Ursus arctos) is an endangered species across Europe and largely extinct in the western part of the continent.  "Unfortunately, we lack considerable knowledge about these few remaining viable bear populations, including basic data such as population size and connectivity," says Dr. Carsten Nowak, wildlife geneticist at Senckenberg. So the Balkani Research Society sampled more than 200 scat, hair and tissue samples of the species across Bulgarian bear habitats. Individual DNA profiles generated at the DNA laboratories of Senckenberg and the LOEWE Biodiversity and Climate Research Centre in Frankfurt (BiK-F) finally provided hard data on the population status in the country.

During the analysis, PhD student Christiane Frosch saw an unusual pattern: several individual profiles collected in three regions in the main mountain regions of the country, the Stara Planina Mountains and the Rhodopes, differed considerably from all the other bear profiles. 

Samples from the Carpathian mountains in Romania provided by bear conservationists of the local Milvus Group perfectly matched the unusual Bulgarian DNA profiles. But those regions are several hundred kilometers apart from each other and the generally high genetic difference between the populations does not suggest high rates of exchange. While possible that good long-distance dispersers like bears could make it from Romania to Bulgaria by themselves, the researchers were skeptical.

With the question of where the bears came from solved, it was time to figure out how they got there.

Communism stunk for everyone but dictators

They found a more reasonable explanation: during the era of communism some Eastern European dictators were passionate bear hunters. Supposedly the Romanian dictator, Nicolae Ceausescu (1918-1989), shot more than 1000 bears in his lifetime, which shows he was as misguided about his food as he was his politics; bear meat is bitter and stringy.

Clearly, the constant success of a bear-hunting dictator is going to fall to numerous assistant hunters and game wardens and raising bears in captivity. And diplomacy meant they might get sent to friends. In Romania and Bulgaria, people claimed that large Carpathian bears were brought to Bulgarian enclosures be military planes and released in order to spice up the less impressive local bear population.

It's not all anecdote. One of the places where translocated bears where kept, the Kormisosh enclosure in the Rhodopes, does still exist. Several of the “alien” bear genotypes were found in the vicinity of this enclosure. 

Brown bear in Kormisosh enclosure, Bulgaria. © Aleksandar Dutsov, Balkani Wildlife Society

More than two decades after the breakdown of socialism in Eastern Europe researchers from Germany, Bulgaria and Romania confirm a curious legend: aerial dispersal is not restricted to plants, insects, spiders, or birds. Occasionally, this might also involve bears, the heaviest land predators on earth.

Citation: Nowak, C.; Domokos, C.; Dustov, A.; Frosch, C.: Molecular evidence for historic long-distance translocations of brown bears in the Balkan region; 2014, Conservation Genetics.