Written by America’s National Parks: Yellowstone filmmakers Alain Lusignan, Oliver Goetzl and Ivo Nörenberg
Life in Yellowstone can be harsh and challenging, especially for bison calves. From the day they are born, they face constant danger from predators such as wolves and grizzly bears. But they also face other types of dangers from their environment. In springtime, as the bison undertake their seasonal migrations to fresh spring pastures, the herds must cross rivers swollen by melt-water. Calm rivers become rushing brown torrents, carrying trees, stumps and other debris downstream. Crossing these rivers is challenging even for adult bison, and small calves have no choice but to follow their mothers into the waters.
This is one of the more dramatic seasonal events in Yellowstone that we wanted to capture on film. To tell the whole story, we needed to film all aspects of the river crossing. One of the most challenging parts, however, was predicting exactly where this would happen. Locations like Lamar Valley are long and wide, and herds of bison can cross almost anywhere. It was important to be in position to film the crossings before the bisons arrived at the river, so as not to disturb them. But most cases the herds crossed just out of filming range, which meant weeks of frustration.
It was also very hard for us to watch bison, particularly the calves struggling in the river. Even from far away, you can hear their deep grunting and breathing as they fight against the current. Cows and calves often get separated, and we witnessed calves being swept downstream out of sight. Some areas of the river were particularly treacherous, where young calves could get swept down into rapids and canyons.
One day we found a calf that has been separated from its mother, alone on an island in the river. The calf had survived the crossing, but with no adult bison anywhere in sight, it was in danger of becoming an easy meal. The calf stayed alone on the island for two full days, even with wolves prowling the riverside not far away. Near the end of the second day, just as it was getting dark, a wolf noticed the lone calf, and approached it for the kill. What followed was one the most dramatic encounters we filmed for the Yellowstone episode.
Full of cares, we witnessed as the wolf lunged and started biting the calf, but the calf wouldn’t give up without a fight. As the bison calf and wolf struggled together, we suddenly noticed something running toward them. Out of nowhere, the calf’s mother had appeared, charging to the rescue! The wolf, also noticing the cow’s sudden appearance, broke off the attack. Incredibly, while the wolf’s back was turned, the young calf began charging the wolf from behind! Still filming the entire encounter, we realized that the bison calf quickly reunited with its mother. Just as the light was fading, the wolf lay down on the ground, dejected, and watched the cow and calf walking safely away together.
Watch the dramatic scene now:
Don’t miss America’s National Parks: Yellowstone Sunday at 8/7c on the National Geographic Channel.