A Look Back

Bicycles on the terraces.
Early Attempts at Modifying Bear Behavior in Yellowstone National Park

Kerry A. Gunther & Mark A. Haroldson with written descriptions by C.J. Buffalo Jones (undated manuscript) and Olaus Murie (1944)

From Yellowstone Science 23(2): 2015, pages 83-87.

Yellowstone bears spend up to six months hibernating in winter dens without eating or drinking. Because of the long period of fasting and the need to accumulate large fat reserves for hibernation, bears are a very food motivated species for the 3-4 months prior to den entrance. This food motivation combined with their intelligence, adaptability, and omnivore generalist lifestyle, allows bears to quickly learn to exploit new food resources, especially high-calorie anthropogenic foods. Shortly after the establishment of Yellowstone National Park, grizzly bears and black bears learned that people and their camps, developments, and garbage piles provided easy sources of concentrated, energy-rich foods. In addition, many bears became bold enough to break into tents, buildings, and vehicles to obtain anthropogenic foods, often causing considerable property damage and sometimes injuring people in the process. Although lethal removal of food-conditioned bears provided a short-term solution to the problem, many park visitors, staff, and managers were opposed to this strategy and instead sought non-lethal methods to change bear behavior. Aversive conditioning is one method of attempting to modify undesirable behavior in wildlife. In the context of bears in Yellowstone, aversive conditioning is defined as the use of negative stimuli in an attempt to permanently alter a bear's behavior, with the goal to reduce human-bear conflicts. Attempts at aversive conditioning of bears date back to the early history of the park.

During the park's infancy, and prior to implementation of formal bear management programs, there was some informal bear management being practiced (Schullery 1992).Bears that entered permanent camp facilities, where visitors could rent tent-cabins by the night, were sometimes fed meat with broken glass in it or sponges fried in grease (Schullery 1992). These efforts may have been intended to kill the problem bears, or to make them miserable enough (a form of taste aversion) to teach them to stay out of the tent-camps.

One of the earliest formal attempts at aversive conditioning of bears in the park was conducted by Park Game Warden C.J. "Buffalo" Jones.Buffalo Jones was a colorful, old frontier character appointed as Game Warden of the park by the Secretary of the Interior in 1902 (Schullery 1992). Jones' flowery and sometimes biblical descriptions of his duties as Game Warden provide us with interesting insights into his early attempts at modifying undesirable bear behavior.In Buffalo Jones' own words:

When I arrived at the Park, it did not take long to find that the bears were making life miserable for the people who were trying to camp through Wonderland.In fact, they were molesting the hotels and road camps, where the men were stationed to build new roads through the park.Even the old veteran road builder, Mr. Kelly, who had in charge, a hundred or more men, told me in a tremulous voice "either me or the bars has got to git out of the park", and Capt. Waters, who with his family lived at the lake, and had the transportation of passengers across that delightful and picturesque body of water, was tired of his ruffian neighbors of the forest. But the men who suffered the most, at least in feelings, were the men who had charge of the dairies at the various hotels.The bears must have surely migrated from Canaan, where flowed the milk and honey, for their fondness for the one, is only exceeded by their greed for the other, and just as sure as a pail of milk was out of the hands of a milkman, a bear would have his snout in the pail, and if the man dared to interrupt and pressed him to hard, he would seize the rim of the bucket, and scamper off to the woods, and that was the last of the pail, to say nothing of the milk.

Buffalo Jones went on to say…..

The situation was just this: either the bears must be killed, made wild again or the Park must be closed to traffic and pleasure parties. To be sure the last proposition was not to be considered, so either they must be killed or made wild. It would require drastic measures to accomplish this latter measure, for so much affection had been lavished upon them by the maids, they had become very gentle.When it was passed around that I intended to punish the creatures to make them afraid of their friends, I had the whole park up in arms against me. The managers of the hotels said it would interfere with their custom, for the tame bears were one of the chief attractions, and the girls nearly went into hysterics when my plans were known.

Mr. Jones further stated….

I saw that something desperate would have to be done, and I tried pelting the intruding animals with fine mustard shot, thinking to sting them good, and make them shy.This helped a little, but did not prove altogether satisfactory. I then arranged a block and tackle, with ropes over a large limb of a tree, dropped a noose on the garbage heap where the bears came to feed, and when a bear stepped into it, pulled the rope until it was securely about the foot, then with the aid of a soldier or tourists, drew him up until they stood on two feet and with a smart willow switch, I gave it a severe chastisement. This new method of treatment rather caught the bears unawares and appeared to break their spirit for to be detained against their will is a disgrace to wild creatures and they remember their punishment all their lives and teach their offspring to beware, being sure that every men's hand contains a willow switch and a rope.

However, by 1905 park management had ordered Buffalo Jones to quit the practice, and he resigned his position as Game Warden shortly thereafter (Schullery 1992).

In the 1940s, bears were still causing considerable property damage and still inflicting injuries on many park visitors;therefore, park managers continued experiments with aversive conditioning to keep bears out of developments.In 1943, wildlife biologist Olaus Murie was assigned the task of studying the life history of the park's bears to provide information to managers that could be used to solve the park's bear problems. In his 1943 progress report on the "Yellowstone Bear Study," Murie (1944) stated:

The bear situation in the Yellowstone is by no means unique. The bear problem is not confined to national parks, but is national in scope. Wherever man enters the bear habitat for any length of time, bear-man relationships are bound to become complex. It is true, however, that this relationship has become most acute in the Yellowstone because of man's long residence there, the great concentration of people, the protection of bears, and the attitude toward the bears assumed by park visitors. But speaking more generally, bears are likely to make themselves familiar whenever they find camps in their domain and are given encouragement by the presence of garbage or unprotected food. The bear problem has appeared in several national parks. Bears also become familiar around lumber camps, or any construction camp in the woods where garbage becomes available.

I have seen published accounts to the effect that many bears became pets at the construction camps along the Alaskan Highway. Thus we have a broad picture of bear reactions, on the basis of nation-wide experience. The outstanding feature, as I see it, is the tendency for bears to become tame and to lose the fear of man when they come in contact with him frequently. Animals in general have this tendency, of course, but some respond more readily than others. The bears seem to lose all fear and reach the point where they are not unduly alarmed when hit with sticks or stones to drive them away, or when shot at, or otherwise harassed by irate campers who have suffered bear depredations. The bear retreats far enough to get out of the way, then goes the rounds seeking new advantages. Tourists have this in common too: They seem to lose all fear of bears.Perhaps there are two reasons for this.Familiarity with bears poking along the highway like bums seeking a hand-out, or coming to the doors in camps eternally seeking garbage, tends to dispel any previous impressions of a heroic or dangerous animal of the forest.

Murie (1944) described an experiment where he used an electronic cattle prod attached to a long pole to administer aversive conditioning to black bears in an effort to get them to stay out of the Fishing Bridge Campground.Murie (1944) stated:

I am convinced that the electric prod held in the hand, or any similar device, is not effective. In fact, any punishment inflicted personally, in such a manner that it is obvious to the bear that a person is involved, is not likely to work. Experience has shown that the bear learns to recognize the particular person or car that administers the shock or other punishment, and he simply avoids that person or car in the future, but does not fear other persons or cars."

Murie concluded it was very difficult to drive bears off once they had acquired the habit of seeking garbage near human dwellings. After studying the food habits of grizzly bears and black bears in the park, Murie (1944) concluded:

There is ample natural forage for bears and that garbage is not required to support the bear population. It is further concluded that although the bear is largely a vegetarian, it has a strong desire for meat and foods included in garbage and that its actions are unquestionably influenced by the presence of such food resources. It is pointed out that the bear is a shrewd, unusually resourceful animal, easily adaptable to many situations, easily tamed in the presence of men, and that therein lies our problem. Another fact enters the problem—misconceptions in the minds of tourists, their assumption that the park bear is a harmless or semi-domesticated animal. Driving bears away, inflicting punishment on them personally, are no permanent help. Electronic devices have proven fairly successful, when operated automatically and dissociated from the presence of man. It is planned to continue food habits studies, with special attention to spring and early summer, and the relationship with elk in the calving season. It is also planned to experiment with electric devices on garbage cans and car windows as deterrents in special cases, to cure certain individual bears of their raiding habits. It is recommended specifically to produce a bear-proof garbage container as the first step, and obtain full cooperation of the concessionaire, prior to any intensive program of enforcing regulations on tourists.

By the mid-1970s, the park had successfully solved most of its bear problems associated with bears conditioned to human foods, and aversive conditioning was no longer necessary. However, by the early 1980s a new management challenge had surfaced. Bears that were habituated to people but not conditioned to human foods, began foraging on natural foods in roadside meadows in close proximity to park visitors (see "Habituated Grizzly Bears: A Natural Response to Increasing Visitation in Yellowstone and Grand Teton National Park," this issue). Some bears even became habituated enough to feed on natural foods within park developments. With this new challenge and in an effort to prevent bear-jams and associated traffic congestion, aversive conditioning resurfaced as a potential method to keep bears from foraging in roadside meadows during daylight hours. In addition, aversive conditioning was used to teach bears, even those not seeking human foods, to stay out of developed areas.

In the 1980s, the park began deploying what was referred to as the "Bear Thumper Gun." The Bear Thumper Gun had a 32 mm bore and used a black-powder charge to fire 1 1/4 x 3 inch plastic bottles filled with 30 cc of water, making a 602 grain projectile. The load traveled about 144 meters per second with 300 foot pounds of energy. The bottles had a wide surface area and collapsed upon impact. The theory was to inflict pain on bears without risk of penetration, injury, or death.The Bear Thumper Gun was used in combination with a portable public address (PA) system that played taped calls of California quail (Callipepla californicus, a species not found in Yellowstone). The idea being that bears would associate the quail call with the pain inflicted by the Bear Thumper Gun, so they could eventually be made to leave the roadside or development simply by playing the quail call.Driving through the Bridge Bay Campground, with the call of the California quail blaring over the PA system, most visitors went about their normal business of setting up tents, grilling burgers, etc., without taking any notice of the quail call at all. Of course, most visitors probably did not know that California quail were not found in Yellowstone, so the quail call probably sounded perfectly wild and natural to them.

Using black powder in the Bear Thumper Gun required that the reloadable shell casings and barrel be cleaned frequently to maintain accuracy. Unfortunately, even with a clean barrel the Bear Thumper Gun was only accurate out to about 20-25 yards. If lucky, one might hit a bear at 30 yards—beyond that range you could not expect to hit much. In addition, the black powder left such a large cloud of smoke it was difficult to tell whether a bear had been hit at all. Regardless, when feeding on natural foods along roadsides, bears learned to move just out of range (35-40 yards) anytime the Bear Thumper Gun was pulled from the truck. Bears seemed to recognize park vehicles, uniformed park staff, and the distance at which the Bear Thumper Gun could be effectively fired. Bears also appeared to have a much greater pain threshold and tolerance to hazing than the park had staff and budget to counteract (hazing must be consistently implemented during teachable moments to be effective). Bears had beaten yet one more attempt to modify their behavior.

At the present time, a combination of 12-gauge shotgun-fired cracker shells, bean bag rounds, and rubber bullets are used to haze bears out of park developments. With consistent application, the park has had some success at teaching individual bears to skirt around developments rather than walking through them. The success is likely attributable to several factors, including: 1) providing bear-proof food and garbage storage in park developments, therefore eliminating anthropogenic attractants that lure bears into developmented areas;2) trained personnel are usually present and able to quickly respond to haze bears out of developments, allowing the consistent application of hazing that is critical to modifying bear behavior;3) developments have somewhat distinct geographical boundaries (pavement) identifiable to bears and staff, allowing for hazing to be consistently applied;and 4) developments are areas of concentrated human activity with associated noise and odor, therefore reducing the attractiveness of these areas to bears. Bears are no longer routinely hazed from roadsides because teaching bears to avoid miles of roadside habitat containing abundant natural foods cannot be implemented on a consistent basis and is cost prohibitive. In addition, because the food reward cannot be eliminated, hazing has not been effective at teaching bears to avoid roadside habitat.

Aversive conditioning is not a solution to habituation or food conditioning in bears. It is simply another tool, secondary to visitor education, food storage, and enforcement of regulations for food storage and wildlife approach distances. The dilemma for park managers is how to balance the needs of bears with the expectations of park visitors while providing for the safety of both, and at the same time remaining within fiscal constraints. The next challenge for park managers is to find innovative, cost-effective ways to manage the large numbers of visitors who want to view, photograph, and experience bears, or to develop cost-effective methods to prevent habituation in the face of ever increasing park visitation. In the meantime, highly intelligent and remarkably adaptable grizzly and black bears are habituating and learning to coexist in close proximity to people, so they can survive in a landscape that is increasingly dominated by humans.

Literature Cited

Jones, C.J. (n.d.). [Letters &papers]. Courtesy National Park Service, Yellowstone National Park Library, Map Room Collection. Yellowstone National Park, Wyoming, USA.

Shullery, P.1992. The bears of Yellowstone. High Plains Publishing Company, Worland, Wyoming, USA.

Murie, O.J.1944. Progress report on the Yellowstone Bear Study. U.S. National Park Service, Yellowstone National Park, Wyoming, USA.

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Last updated: December 21, 2015

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