Camera trap footage from the Białowieża Primeval Forest has captured rare evidence of wolves (Canis lupus) hunting European bison (Bison bonasus), challenging the long-held classification of the species as having no natural predators. The encounter, documented in a study published in Ecology and Evolution, shows a pack of five wolves attempting to isolate and kill a newborn bison calf.
Why the European Bison is No Longer Strictly Non-Prey
For decades, biologists categorized the European bison as a non-prey species, noting that healthy adults face no threats from predators other than humans. However, the new video evidence confirms that wolves do actively target bison, particularly when packs are large enough to overcome the herd’s defensive maneuvers. According to the research conducted by Dr. Rafał R. Wijnands and Dr. Tomasz Borowik, this interaction suggests that bison are a potential, albeit difficult, food source for wolf populations.
How the Bison Herd Defended the Calf
The footage recorded in the Białowieża Primeval Forest illustrates a complex social defense strategy. When the five wolves initially surrounded the newborn calf, the mother and other cows attempted to drive the predators away. Despite the wolves successfully biting the calf’s neck and attempting to drag it from the group, the adult bison formed a protective circle. This defensive formation effectively halted the attack, forcing the wolves to retreat. This behavior highlights the importance of herd cohesion in the survival of bison calves, which are significantly more vulnerable than the massive, powerful adults.
Historical Context of Wolf-Bison Predation
Wolf attacks on bison were documented more frequently in the 19th century. Historical records from the Białowieża forest—which served as a royal hunting ground—indicate that approximately eight bison kills by wolves were recorded annually between 1840 and 1849. Following the extinction of the European bison in the wild in 1919 and their subsequent reintroduction in 1952, confirmed predation events became exceptionally rare. For decades, wolves in the region focused on smaller, more accessible prey like roe deer, red deer, and wild boar.
What This Means for Future Wildlife Management
The potential for increased predation has implications for the future management of bison populations. Researchers suggest that as wolf packs grow in size—partly due to a hunting ban enacted in the late 1980s—the frequency of these attacks may rise.
If wolves begin to predate on young bison more regularly, they could function as a natural regulatory force within the ecosystem. This natural regulation might eventually assist in mitigating human-bison conflicts by stabilizing the herd size through ecological rather than anthropogenic means.
Key Observations
- Location: The footage was captured in the Białowieża Primeval Forest, a protected area on the border of Poland and Belarus.
- Species: The event involved Canis lupus (gray wolf) and Bison bonasus (European bison).
- Defense Mechanism: Adult cows utilized coordinated group defense to protect the calf, a behavior that ultimately repelled the predators.
- Ecological Impact: Increased predation could shift the role of wolves from opportunistic hunters to active regulators of bison population density.