Behavior Sequence: Baby Bison Falls into Pond
Last spring in Yellowstone was relatively cold and the snow was slow to melt. Even the sandhill cranes got here too early to find much to eat. Many Yellowstone bison, especially the females and the young, leave the park in the winter and return in the spring. The northern bison herd follows a well known path from the Gardiner, MT area through Mammoth to Yellowstone’s Lamar Valley each spring. The path takes them along the edge of Blacktail Ponds. The ponds can be a treacherous place for bison. It is not uncommon for full grown bison to fall in and die in the as the banks are so steep it can be impossible for them to get out. In the spring when the bears emerge from hibernation the dead bison provide much needed protein and the wolves benefit too.
Early one spring morning a herd of bison was making its way around Blacktail Ponds. It was so early in the spring the herd only had one newborn calf that could not have been more than a day or two old.
As the herd made its way around the pond a few chose to take a wet shortcut. But most of the bison went around the water. The newborn calf’s mom led it around the pond. As it rounded the edge of the pond the new calf was pushed by a yearling bison, maybe a jealous older sibling. Although most bison calves are weaned when they are seven or eight months old it is not unusual to see a yearling still nursing.
The newborn’s mother knew the calf was in trouble but wasn’t equipped to do anything about it. The pond had just melted and the air temperature was well below freezing. An adult human can survive at this low temperature for about 15 minutes. But a newborn bison calf has less fat and more surface area than an adult human. At this point it had been in the water about 12 minutes and was exhausted. One effect of hypothermia is muscles stop working so it was getting increasingly difficult for it to get out. Adult bison have failed to get out of this pond and frozen to death.
I guess it is a good thing that baby didn’t know that because suddenly it mustered all of its strength and actually got out! It was pitiful looking, but it was out. I realized as it stood there shivering that it must have been one tough little baby. Its mom came and licked it a little and allowed it to nurse.
Mom decided it was time to move on but had to return to her baby several times to coax it to start walking. It finally did start walking in the freezing cold air.
It had all of the rest of what became a sunny day to dry out.
Cinematography by Judy Lehmberg