Encountering a grizzly bear is never a good thing, and I would know. A couple of years ago, I was hiking alone in the Mammoth area of Yellowstone. I was so loving the scenery, consumed by a sense of wonder in such an amazingly beautiful country, that I neglected to keep making noise to let any bear know that I was approaching.
When I turned a corner on the trail, there was a 300 pound grizzly sitting by a bush just about 100 yards in front of me. I was lucky; he saw me first and took off in the same direction I had been heading. I retraced my steps and headed for the nearest bar. (Yes, it was 10 a.m., but when a bear is involved, there’s no room to judge.)
Unfortunately, others encountering grizzlies have not been so fortunate. In 2010, for example, Wyoming had a record 251 bear-human “conflicts,” which included attacks on people, livestock and property. In July 2010, a grizzly killed a camper and injured two others in a national forest in Montana near Yellowstone. The following year, two hikers were killed at the park in separate attacks, the first such deaths since 1986. Most recently, on August 15, two hikers at Yellowstone were wounded by a grizzly that was warded off when a second pair of hikers used bear spray.
Bear-Human Encounters Likely to Increase
Thanks to climate change, this pattern of human-bear encounters in Yellowstone National Park is likely to increase as a scarce supply of nuts forces hungry grizzlies to seek food closer to the park’s popular tourist areas.
“We are expecting an increase in human-bear encounters and we are reinforcing safety messages,” said park spokesman Al Nash.
Officials with the park and two national forests that border it said numerous recent sightings of bears seeking berries and other foods near roadways and popular trails prompted them to issue the advisory, which calls on outdoor enthusiasts to take precautions like carrying bear spray and hiking in groups.
What‘s Going on Here?
Conservationists say that in recent years climate change has caused a decline in whitebark pines, which produce the nuts that are a food source for grizzlies and black bears.
Specifically, the onset of warmer weather and milder winters has led to the populations of mountain pine beetles exploding and their range expanding; as a result, whitebark pine trees have been killed by the thousands in recent years.
The beetles burrow under bark of the trees to lay their eggs and infect the trees with blue stain fungus, which blocks the trees’ flow of nutrients and water. That, along with the feeding of the beetle larvae once they hatch, kills the trees within a few weeks.
Since the whitebark pine is a keystone species in the Yellowstone ecosystem, with its highly nutritious nuts providing food to multiple bird and animal species, this is bad news for the park. It’s also bad news for innocent tourists, who may now be more likely to come in close contact with a grizzly searching for food.
This is not even the only instance of decimation by these beetles.
Exploring Rocky Mountain National Park last year, I drove on Trail Ridge Road up from Estes Park to the high point, over 12,000 feet. As I descended on the other side, I saw miles upon miles of decimated hillsides because the mountain pine beetle has also infested the lodgepole pine. Of the 1,500,000 acres of what used to be lodgepole pine, about 70% of them are now bare, thanks to warmer temperatures.
As we keep learning, climate change affects everything in nature, and it’s not good.
All photos via Thinkstock