Bears & Elk
One afternoon early in June, I spotted a herd of about forty cow elk, some with calves. Where initially the herd was scattered throughout the sage along the forest edge, they had now moved toward the road and were gathered together in a tight cluster. They were nervous, gazing toward the trees, ears cocked forward. They paced anxiously, some spinning in circles. I could hear a lot of mewing and a few barked alarms. These are clear signs a predator was near, probably the grizzly bear and cubs I had spotted in the area the day before. The herd’s nervousness grew until suddenly the lead cow, followed by the rest of the herd, made a break, streaming across the road until the last few had escaped – all but one.
One elk hesitated. She appeared conflicted. She clearly wanted to flee with the herd. Instead, she spun, circling back multiple times. Then, in a seemingly crazy act, she trotted quickly towards the forest where a bear likely lurked. She began moving back and forth along the edge of the trees, running away, and then back again. Why would she do this? Only one reason made sense: she must have hidden a calf there.
After a few minutes passed, I heard a faint, tiny squeal, a barely audible squeak. Something might have killed the calf, I thought, but I wasn’t certain. Minutes later, I spotted movement. A grizzly bear and at least two cubs were in the deep sagebrush at the edge of the conifers. The bear fed, rocking back on her haunches and jerking her head upward.
Elk calves serve a major role in the Yellowstone ecosystem: feeding predators. While a grizzly’s diet consists of roughly 80 percent vegetation, meat is much higher in digestible protein, important after coming out of hibernation in early spring. An elk calf weighs about 40 pounds at birth, and can be taken and eaten quickly. From about mid-May until late June, newborn elk calves are particularly vulnerable. Calf mortality is about 30% in those first several weeks, chiefly through predation by bears. After that, the calves will usually elude a bear, but then the wolves and cougars take over. Life in the wild is harsh, and often much too brief.
A mother elk will hide her newborn in the sage, as the calf is not yet strong enough to follow mom for long periods. Lying down, they are concealed and their scent tends to lie low to the ground rather than dispersing in the wind. However, bears have a phenomenal sense of smell. A grizzly will use a blind search strategy to hunt for newborn calves by zigzagging through the sagebrush sniffing the ground. Using an alternative ambush/chase strategy, when a grizzly spots a group of cow elk, it may lie in ambush and then charge the center of the group to separate and chase down any calves. If that fails, it will begin searching that spot for any bedded calves.
A little research gave me clues to what the mother elk was doing. Trying to protect their calves, mothers will actually approach and cross in front of the bear and may even charge in an attempt to distract it and trigger it to give chase.
I watched the mother elk with a mix of sadness and fascination. Not willing to leave her calf, the distraught elk paced anxiously past the bears. She disappeared only to return, moving dangerously close to the bears. She was within fifteen feet of the grizzlies as one bear raised its head. For a moment, the two stared at each other. Yet it was too late, an act of futility. Was she still trying to distract the bears, or simply see her calf?
I was deeply moved by the elk’s dilemma – yield to her instinct to flee or her instinct to protect her calf. She chose her calf. Near sundown, the bears finished feeding, and after resting for a short while they rose and ambled away, weaving through the sagebrush. The elk stayed until dark.
Today’s Field Note was written by Shane Morrison in the Field Notes Writing Workshop at the Montana Natural History Center. I’m Allison De Jong for Field Notes, brought to you by the Montana Natural History Center, providing natural history education for schools and the public throughout Montana. To find out about upcoming events and programs at the Center, call 327.0405, or visit our website at MontanaNaturalist.org.