A pack of wolves attacked a herd of European bison in Poland's Białowieża Primeval Forest last September, targeting a newborn calf in a rare recorded encounter.
The footage, captured by researchers using a camera trap, shows seven wolves distracting adult bison and biting a calf twice during a 20-minute chase. Adult bison charged the wolves with their horns, and the herd eventually surrounded the calf to drive the predators away. Robin Wijnands of the Polish Academy of Sciences said the recording surprised her team, as they had not expected wolves to hunt bison when other prey is available. The European bison population has recovered to around 9,000 after near-extinction in the wild a century ago. Wijnands and colleague Tomasz Borowik noted that wolf predation, though uncommon, could help stabilize bison numbers without causing steep declines. Oswald Schmitz of Yale University called the capture a lucky occurrence given the low odds of positioning a camera at the right place and time.