Secret of two bears

The Secret of the Two Bears

Thanks to these analyses, we are gaining a better understanding of two bears whose skulls have survived for thousands of years in the Tatra caves. One was discovered in the Great Snow Cave in the heart of the High Tatras in Poland, the other in the Low Tatras in the Demänovská Ice Cave in Slovakia. Both skulls belong to the same subspecies—the Eurasian brown bear (Ursus arctos arctos). The find from Poland belonged to a young adult female around 6–8 years old, while the find from Slovakia belonged to a young adult male, approximately 10–12 years old. The female bear from Poland lived about 4,900 years ago, and the male bear from Slovakia lived about 4,200 years ago.

 

The climate at that time

Both individuals lived during a transitional period between a warm, humid climate and gradual cooling. At that time, the climate in the mountains was stable and humid. The tree line extended much higher than it does today—dense spruce forests grew even at an elevation of 1,750 meters above sea level.

 

Bear Family Tree

DNA analysis showed that both bears, despite being separated by centuries, belonged to the same Carpathian family as the bears living in the Tatra Mountains today. The ancestors of the female from Poland originated from the north (they belonged to mitochondrial haplogroup 3a), while the lineage of the male from Slovakia originated from the Balkans (mitochondrial haplogroup 1b). Despite their different genetic lineages, nuclear DNA analyses confirm that all Tatra bears formed a single homogeneous population, and the individuals studied are genetically indistinguishable from bears in today’s Carpathian population.

 

 

The Good Gene

It turned out that the bear from Slovakia had much higher “genetic diversity” than modern individuals, which allows the population to better adapt to environmental changes. This means that over the course of a few thousand years, the genetic health of the Carpathian population has deteriorated—likely as a result of isolation and environmental pressures.

 

The Final Sleep

An analysis of their teeth also revealed a sad secret: the female from Poland died during hibernation, and the male from Slovakia died just before it began.

 

From the bears’ diet

An analysis of strontium isotopes in their bones and teeth confirmed that they had never fed in the same territory. Although both individuals lived in similar environments, their diets differed. The female from Poland followed a high-protein diet—she consumed much more meat than her Slovak cousin. The male from Slovakia preferred a diet based on plants and forest fruits.

 

There’s no place like home…

Isotope analysis shows that these animals were strongly tied to the local landscape—just like today’s Carpathian bears. This means that during their adolescence, neither bear traveled long distances; they stayed within their favorite territories.