While reviewing images for her doctoral research, Polish Academy of Sciences ecologist Robin Wijnands saw something pretty wild. A camera installed in the Bialowieza primeval forest in eastern Poland recorded wolves (canine lupus) attacking a European bison (bonasus bison) herd.

The video, recorded in September 2025 and described in a study published in the journal Ecology and EvolutionIt begins with five wolves entering the scene. Three bison cows chase wolves, inadvertently leaving a newborn calf vulnerable. The wolves then attack the calf, bite its neck and try to drag it away. That’s when two cows come to his rescue and charge towards them. The wolves try to catch the calf a second time, but this time the entire herd surrounds the calf and the wolves give up the attack.

Wolves attack European bison

“We captured this event by pure chance, which makes it even more special,” says Wijnands. popular science. Wijnands is also a co-author of the new study and her research monitoring the behavior and activity of large mammals in the Bialowieza primeval forest. The images excited and surprised the researchers.

“This raised many questions: Why would wolves seek out difficult prey like the European bison? How often do predation attempts actually occur, and how often are they successful?” says Wijnands.

A search of the available scientific literature revealed that there are actually many historical reports of predation on European bison. However, only a few of these recent attempts have occurred recently and none have documented evidence of a wolf grabbing an individual.

The study raises interesting questions about the reintroduction and conservation of the European bison. The species was hunted to extinction in 1919, but was reintroduced to the forests of Poland in the early 1950s. Today, around 6,200 European bison live in the wild and are often described as the “king of the forest” and considered a non-prey species.

“At this time, most reintroduction initiatives do not appear to include predation risk or the presence of predators in habitat suitability analyses,” says Wijnands. “We believe it should be considered in such analyses, as it could potentially affect small reintroduced populations.”

“However, even if predation occurs more frequently than we think, we do not expect a sharp decline in European bison populations,” he adds, “especially when easier and more accessible prey is available.”

Wijnands hopes the study opens the door to more research into interactions between bison and wolves and their possible consequences, although he also notes that the work focuses on a single interaction and no definitive conclusions can be drawn from it.

“We mainly wanted to share this rare and special observation and show that there are still many unknowns about the interactions between the European bison and the wolf,” he says.

2025 PopSci Best of what’s new

The 50 most important innovations of the year