Bears in the Neighborhood – Part 3

By Jeff Keay

Pulling it Together to Live Safely With Bears

This is Part 3 of a three part series.

The year was 1969, and at 20 years old I had just completed two years of college and anticipated joining the U.S. Army. Ready for adventure, my brother, Brian, his wife and her sister, and I headed to Michigan’s Upper Peninsula for a week-long canoe trip. What is now the Sylvania Wilderness promised remote lakes and plenty of solitude. We launched our canoes into the northern end of Clark Lake and enjoyed a pleasant paddle, under a clear sky and calm winds. A campsite on a peninsula provided my first experience with loons, as their eerie call echoed across the lake. I thrilled at the northern hardwood forest and peacefulness of our venue.

As the sun lowered in the sky, my brother and I loaded our food into my backpack. I tossed a rope over a tree branch, tied it to my pack, and hoisted it into the air. On previous canoe trips, Brian and I had food taken by raccoons. Without thinking very deeply, we considered them our biggest challenge. We suspended the pack in the air too high for a raccoon to reach.

In the middle of the night, we were aroused by banging and slapping sounds. Peeking out of my tent, I watched a black bear use my backpack as a piñata. A hole ripped in the side of the pack allowed food to fall to the ground with each powerful slap of the bear’s paw.

“Hey bear! Hey bear! Get out of here.” I yelled. The bear ignored me.

My brother, standing on a picnic table, banged pots and pans, adding to the racket. All to no avail.

“Jeff, stand back,” Brian said, “I’m going to poke it with a canoe paddle.”

After several prods with the paddle, it became clear the bear wouldn’t budge. It was not about to leave the bounty it had dislodged from my pack.

“Jeff, while the bear’s eating food on the ground, I’ll grab the pack, you cut the rope, and I’ll run the food off, away from the bear.”

We saved most of our food, but we still had a bear eating, right in the middle of our camp. Finally, out of desperation, we tossed a bucket of water on the bear. That caught it by such surprise that it leaped to the tree trunk, exposing its full size. That bear had to weigh over 200 pounds! What were we thinking? Emboldened by our success, we persisted the torturous water bucketing and the bear wandered off.

Later that evening I woke to the sound of footsteps and panting circling our tent. Then I heard the obvious sound of a large animal climbing the tree that supported our food; it had to be the bear. We suspended our food quite high this time, and out of the bear’s reach. A short time later the sound of shredding bark suggested the bear had come back down to the ground. Brian held his breath as he listened to loud, hollow breathing when the bear poked its head inside the door of Brian’s tent, and about one foot from my brother’s head. Recognizing there was no food smell inside, the bear slipped away into the night.

Bears may have a natural fear of humans, but they can quickly lose that fear when they discover people aren’t a threat. Once they recognize that people harbor delicious food, they will eagerly bully us in attempts to get access to our nutritious banquet, and they can be persistent.

In the previous section, we concluded that the naturally regulated grizzly bear population in Denali National Park was food limited, that is, the amount of nutritious food available put a cap on how many bears the population could sustain. If you increased the amount of food, the population would increase. We also learned that bears are self-regulated. There is an intrinsic mechanism in bears that controls the bear population size in response to the amount of food available. It keeps the population numbers low enough, that it allows females to maintain high reproductive rates during poor forage years, in order to take advantage of good nutrition should it be available the following year. That regulatory mechanism acted upon cub, yearling, and two-year-old survival. Such populations are said to be at carrying capacity. Remember, carrying capacity refers to a theoretical cap on how many animals a habitat can sustain over the long term.

In contrast, bear populations that exist below carrying capacity, such as those that are heavily hunted or those expanding into new territory, likely have sufficient natural food available to regularly meet individual animal needs. Fat and healthy bears, that have no previous experience around people, are less likely to risk exploring human habitations in search of food. Bears, however, are very opportunistic and any accidental encounter will be remembered and tried again if rewarded.

In the section on Yosemite National Park, we learned that human food is very nutritious for bears and highly sought after once discovered. Bears are bullies and become very bold when they realize humans do not pose a threat. Educating the public is necessary but will not resolve conflicts with bears. Law enforcement is essential but will never be able to completely eliminate available human foods. Attractive nuisances, such as fruit trees and bird feeders, just like our unsecured food and garbage, will bring bears into developed areas and close contact with people, exacerbating the problem. Bears are insanely curious and tear things apart in search of food, and can cause extensive property damage. Bears damage their claws and break their canines when forcing their way into automobiles or other structures.

Although what we learned in Yosemite will apply directly to elsewhere in North America, all that we learned in Denali may not. We must be cautious, because there are some ecological differences. Let’s use Yellowstone National Park and the surrounding ecosystem as an example. Adult female grizzly bears have a longer foraging season in Yellowstone, since they den for just over five and a half months compared to seven months in Denali. The Yellowstone Ecosystem also supports a much larger number ungulates, especially elk and bison, that become available to grizzly bears as carrion and newborn young. Therefore, adult female grizzly bears in the Yellowstone area have had access to substantially more terrestrial meat than Denali females. The greater diversity of foods also gives grizzly bears in the Northern Rockies alternate food sources when one item becomes unavailable.

Yet the concept of naturally regulated grizzly bears being food limited and self-regulated is widely accepted among biologists. Food limitation, by definition, means that at some point Yellowstone Ecosystem grizzlies will bump up against a nutritional limitation. How that will be reflected in adult female physical condition and cub and yearling survival is still unknown, but I would expect periodic nutritional stress. Nutritional stress means bears will be highly motivated to search out and exploit new sources of food.

The point is, that when a bear population (either black or grizzly) reaches carrying capacity, there’s more to it than just a larger number of bears opportunistically discovering human foods. At carrying capacity, there will be the added motivation of nutritional stress. Nutritional stress may occur periodically with normal variations in weather patterns, such as summer droughts, or extended winters. During periods of nutritional stress, especially females desperate to put on weight to successfully raise young, will search for alternate sources of highly nutritious foods. Adult males and subadults of both sexes may similarly be searching for new forage venues, depending on the severity of the natural food shortfall. For example, we experienced higher property damage by Yosemite bears during years in which we observed poorer acorn crops.

Again, considering the Yellowstone ecosystem, the adjacent Island Park, Idaho, had low grizzly bear numbers during the 1970s through 90s but, as of this writing, has been increasing for the last decade or two. At some point we expect that the grizzly bear population in Island Park will reach carrying capacity. We cannot assume that peoples’ experience with bears in the past is what they should expect in the future. Conflicts between humans and bears will increase in the future unless residents and visitors change their behavior, to better prevent bear access to their food and garbage.

If bears fail to experience aversive encounters with humans, they will venture near human habitations and campsites in search of food. Once a food reward is successfully obtained, they will remember and return in time of need. Bears in close proximity to humans put both humans and bears at risk.

The summer of 1979, Bruce Hastings, a graduate student from Utah State University, conducted aversive conditioning trials at Rancheria Falls in Yosemite National Park. His goal was to see if he could train bears to not attack stuff sacks full of food that backpackers had suspended from trees. He filled balloons with hydrogen peroxide and suspended them from trees in various colors of stuff sacks.

Early one evening a small, light brown black bear with a medium-sized white blaze on his chest walked near the tree with Bruce’s suspended stuff sacks. The bear had a blue streamer with a red circle hanging from its left ear indicating bear 273, a yearling male. Eyeing the stuff sacks, the bear made a bee-line for the tree and scampered up. Without hesitation, the young bear reached out with his mouth wide open and chomped down on an orange sack expecting to rip it out of the tree. Clear liquid spewed from the sack and the bear snorted, leapt out of the tree, and ran off into the woods.

The following evening, at about the same time, the same bear walked slowly down the same trail. Bruce’s eyes focused on the bear, anxious to see what it would do. As the bear neared the tree, where the hydrogen peroxide-filled balloons had been suspended, it made a wide detour to avoid getting close to that tree. Following the bear down the trail, Bruce watched as it continued toward other campers, climbed a tree, and reached for an orange-colored stuff sack, complete with a camper’s food.

That experience taught the bear to avoid a particular tree, but not the intended stuff sacks. We never know what associations a bear will make with positive and negative experiences. In Yosemite we occasionally had bears break into automobiles that had no food in them. We believed that those bears had previously received a food reward in those same parking spots or from vehicles of a similar size, shape, or color. Thus, not only careless people, but anyone nearby can be impacted by someone’s careless behavior.

The only effective solution to successfully living with bears is to store food and garbage so it is completely inaccessible to bears. Such storage devices must be simple and easy to use and enclose all odiferous items that might attract a bear. They must secure food and garbage 24 hours a day and seven days a week, because bears will alter their natural foraging cycles to take advantage of any nutritious food that becomes available. Effective food and garbage storage procedures must become engrained as a permanent behavior among residents and readily accepted and implemented by visitors to any community in bear country.

Twenty years after leaving Yosemite National Park to work in Denali, I returned with my family for a week-long camping trip. We stayed in three different front-country campgrounds so we could experience the different habitats and sites throughout the Park. I was impressed with how clean the front country campgrounds were. There was no broken glass in the parking lots nor shredded tinfoil or plastic near the campsites. We saw no evidence and heard no reports of bears causing property damage, all thanks to bear-proof garbage receptacles and food storage lockers in every campsite.

We were, however, roused early one morning in Crane Flat Campground and ran to catch a quick glimpse of a black bear passing nearby. In Tuolumne Meadows Campground, most of us went for a hike, leaving in camp our daughter-in-law, Ryan, and her three-year-old son who needed a nap. Ryan relaxed in a camp chair, mid-day, reading a book, and finally dozed off. She startled awake as a female black bear sniffed her feet. Ryan jumped and twin cubs scampered up a nearby tree. Unsure what to do, with the bear between her and her three-year-old sleeping child, Ryan stood and backed away slowly. The mother bear called the cubs out of the tree and they left without further incident.

Ever vigilant, bears that likely had received a food reward previously, possibly even many years previously, still visited old haunts in hopes of snagging a nutritious meal. If Yosemite can undo such a widespread and extreme condition of bear depredation on human foods, surely the rest of us can prevent it from getting started by being vigilant in storing food and refuse in appropriate containers. It is significantly easier to prevent bear acclimation to humans and our foods, than to reverse the process. We can coexist safely with grizzly and black bears; if humans will do their part.