When Man Becomes Prey

by Cat Urbigkit

  When a reporter affiliated with National Public Radio asked Denali park superintendent Paul Anderson whether it was the agency’s policy to kill bears involved in attacks, Anderson responded in the affirmative, explaining that it is when a bear attacks a person and then identifies it as a food source. Anderson noted that in this case, the bear killed the person out on the gravel bar and then dragged him 150 yards into the brush where he partially buried him after having fed upon him for a period of time.” Anderson continued, noting that the bear then “sat on that cache and wouldn’t allow any other animals or humans to approach them without a fear of attack.”

  Anderson continued: “There have been documented incidents in the past, in other parks in the country, of bears that kill hikers or backpackers or people in the park and then feed upon them, continuing to do so. And we’re not prepared to take that kind of risk here at Denali, given the proximity to hundreds of thousands of visitors.”

  Two months later, tragedy struck again in southeastern Alaska. This time, it was on Chichagof Island, 30 miles north of Sitka. The island is part of a chain of three including Admiralty, Baranof, and Chichagof—the “ABC Islands”—where one of the most dense populations of big brown bears are known to roam. The bears have a reputation for aggression, and research undertaken by a team led by James Cahill of the University of California, Santa Cruz (and published in the March 2013 issue of PLOS Genetics) has demonstrated that the ABC Islands brown bears show clear evidence of polar bear ancestry. Their research indicates this population derived from a population of polar bears likely stranded by receding ice at the end of the last glacial period. Since then, male brown bears migrated onto the islands, gradually evolving into a population that looks like brown bears, with polar bear genetics.

  Passersby noticed an unsecured skiff on the beach, and when they stopped to see if assistance was needed, they were greeted by an aggressive sow bear and her cub. They retreated, but notified authorities of their find. Officials arrived at the site and found a campsite with evidence of a struggle. A trail of shredded clothing and trampled vegetation led investigators to where the bear had cached a man’s partially consumed remains. The man killed by the bear was Tomas Puerta, fifty-four, of Sitka, who was returning to a forestry job site with a load of groceries when boat troubles apparently forced his stop at the beach. Wildlife officials killed at least one of the three bears found at the scene, but little is known about what prompted the attack on Puerta.

  A month later, in November 2012, two trappers were mauled by a brown bear on the Kenai Peninsula. The men were setting snares in a wooded area along a river and couldn’t see each other, but were within shouting distance. One of the men heard a roaring noise followed by his buddy’s yells, so he ran to him and saw his companion being attacked by a brown bear. He yelled at the bear, at which point the bear turned the focus of its attack to him. The man played dead, so the bear returned to mauling its first victim. The bear eventually left and the men were able to get back on their boat and call for help. Both survived their injuries, although the first victim had severe injuries. It is not known what triggered the attack, but when one of the trappers returned to the site to retrieve the snares, he found bear cub tracks. Since the attack was in a remote location, authorities did not attempt to locate the bear involved.

  There were numerous brown bear attacks in Alaska and Canada in 2013, most involving surprise encounters in areas of low visibility, defensive incidents involving sows with cubs, or bears defending carcasses. An exception occurred in an August 2013 attack in Alberta’s William A. Switzer Provincial Park, when a grizzly bear attacked and bit a man sleeping in a tent with his wife. The couple escaped and called for help, while the bear tore through the tent and ransacked the campsite, where food was outside in coolers sitting atop a picnic table. The bear was shot and killed by wildlife officials, who had already tried aversive conditioning on the same bear earlier that day in a different location.

  Making Sense of Bear Habituation

  What conditions allowed Timothy Treadwell to so closely associate with grizzly bears in Alaska for thirteen years before being killed, when hikers in Yellowstone may be immediately attacked when encountering bears there? In 2005, Tom Smith, Stephen Herrero, and Terry DeBruyn published a comprehensive paper examining the overt-reaction distance of brown bears involved in aggressive-defensive attacks on humans. The paper, “Alaska Brown Bears, Humans, and Habituation,” published in the scientific journal Ursus, indicated that the distance at which human presence triggers a charge is primarily a function of bear density (and its associated bear-to-bear habituation); and that greater distances are associated with lower bear densities.

  The paper suggests:

  The nutrient density of an area controls the number of bears it can support.

  Bear-to-bear habituation is a product of bear density. Bears interact more frequently in areas with high bear densities, such as when bears congregate at a salmon-spawning area (thus promoting bear-to-bear habituation).

  Bear-to-bear habituation may assist bear-to-human habituation. In these high-density bear areas, bears seem to have smaller “personal spaces” or overt-reaction distances. Thus, humans can be in closer association to bears than in lower-density populations, in which bears have a larger overt-reaction distance.

  In some cases, humans lose their wariness of bears—this is human-to-bear habituation. This can be facilitated by the degree of bear-to-human habitation of an area. As the authors of the Ursus paper stated, “When people spend time around bears with very small overt-reaction distances, people tend to habituate to these bears, that is, they lose their wariness of bears.”

  Aggregation of bears at feeding sites provides for great bear-viewing opportunities. Wildlife watching is an ever-growing pastime, and bear-viewing areas have been established at numerous locations, with Alaska’s McNeil River Falls in the McNeil River State Game Refuge and State Game Sanctuary, and the Brooks River in Katmai National Park and Preserve growing in popularity. Brown bears are drawn to these areas in July and August as the chum salmon enter the streams to spawn and bears can feast. McNeil River is a state-managed unit that is tucked into the northern portion of Katmai National Park. The entire region is closed to the hunting of brown bears, although there are some hunting areas north of the game refuge, and within the Katmai National Preserve.

  McNeil River Falls has been hosting humans to view brown bear aggregations since the 1940s. The activity became such a popular destination for photographers that state wildlife managers began regulating the number of visitors in the 1970s. The largest known gathering of brown bears in the world happens at McNeil River, and visitors apply for permits to visit, which are awarded through a lottery system. Each day, up to ten permit holders hike to one of the bear-viewing areas with an armed Alaska Department of Fish and Game naturalist. No one has ever been injured by a bear at McNeil River.

  The Alaska Department of Fish and Game’s management plan for the region notes: “The success of the visitor program at McNeil River is largely due to the habituation of bears to people. Habituation is defined as the reduction in the frequency or strength of response following repeated exposure to inconsequential stimulus. One type of response by bears toward people is aggression. Eliminating or diminishing this response creates a safer environment for interaction. Human actions that encourage habituation in bears also, by virtue of lowering stress levels in bears, encourages them to be comfortable around humans, which in turn enhances the viewing program.”

  The plan continues: “Most of the bears in the sanctuary are neutrally habituated. This means that while they are comfortable around people, they do not seek or receive human food or garbage.”

  The distinction between habituation and human food conditioning is an important one. Bears at places like McNeil River and Brooks River are habituated to the presence of humans, not to human foods.

  Human food conditioning of bears requires two elements:

  Bears have fed
on human food or garbage.

  Bears associate humans and/or human development as potential sources of food.

  Larry Aumiller and Colleen Matt, wildlife managers at McNeil River for the Alaska Department of Fish and Game, noted that the agency sought to have brown bears become habituated to humans.

  “We found that, in the absence of a food reward, habituated bears were safer than wary bears,” stated Aumiller and Matt in a 1994 paper, “Management of McNeil River State Game Sanctuary for Viewing of Brown Bears.”

  Highly habituated bears at McNeil River perceive humans as neutral and not threatening. These habituated bears come closer to humans and exhibit fewer signs of stress.

  Aumiller and Matt noted that not all bears at McNeil River exhibit the same level of habituation. Wary bears are not habituated to humans, and tend to flee from human encounters and avoid areas of human development. Neutrally habituated bears generally show indifference to humans, but to varied degrees. For example, some bears stay on the opposite riverbank from humans, while others tolerate humans at very close distances. Wildlife managers report that younger bears tend to habituate more quickly than older bears.

  Habituation to humans at places like McNeil River is learned when bears must come near humans to access a food source (in this case, salmon). To get to the spawning salmon, bears have to overcome their wariness. Sow bears bring their cubs to McNeil River, providing learning experiences and habituation to humans at a young age. Sows in estrus that are already habituated to human presence will also draw more wary males with them to McNeil River, helping the habituation process along in bears that otherwise might not approach the area. Repeated neutral contact with humans reinforces the habituation process. The congregation of bears at McNeil River is an annual event involving many of the same bears—so much so that field guides are prepared to assist viewers in identifying individual bears that frequent the area.

  At McNeil River, bears were habituated to neutral stimulus by consistent repetition. The same viewing areas and camp location are used without alteration. All humans use the same highly visible trails. Activities take place during the same hours each day. Human activity and behavior is tightly controlled during bear-viewing excursions, and there is an overriding emphasis on actions to prevent human food and garbage from being accessible to bears. Sanctuary staff observe individual bears closely and note their behavior, so that any undesirable behavior toward humans is corrected, with the goal of reinforcing habituation. Bears that approach too closely are warned away—sometimes quietly and sometimes in a more aggressive manner, depending upon the bear’s behavior.

  Things operate a little differently at the Brooks River bear-viewing area of Katmai National Park and Preserve. Three bear-viewing platforms are accessed by elevated boardwalks. The platforms have a maximum carrying capacity of forty people, and on busy days, an on-site waiting list is used to accommodate viewing sessions lasting one hour each. Established trails and viewing structures are available for viewers, but visitors are permitted relatively unrestricted access throughout the area. Visitors are required to stay at least 50 meters from any single bear, and 100 meters from a sow with cubs. Campers must stay in the campground, which is enclosed by electric fences, or must camp a minimum of five miles beyond the area. Anglers must avoid the stretch of river near the fish ladder. Federal wildlife managers actively patrol the area, remain onsite, and engage in a variety of hazing practices to deter undesirable bear behavior.

  Making human activities predictable helps to decrease risks of surprise encounters while encouraging habituation. But habituated bears approach people more often than nonhabituated bears, which can pose a danger to campers, according to Herrero.

  “Once such a bear no longer avoids people the stage may be set for entering backcountry camps, especially if the bear has also learned to feed on people’s foods,” Herrero wrote in Bear Attacks: Their Causes and Avoidance.

  BEAR HAZING

  The Alaska Department of Fish and Game has issued a permit to authorized staff of the private, nonprofit Port Armstrong Hatchery to use electronic control devices (ECDs, manufactured by TASER International) to keep bears away from the salmon-hatchery facility located on Baranof Island in southeastern Alaska.

  ECD testing at Port Armstrong began in 2010. “Bears were allowed to access the stream, but if they stepped into the work area, they were tasered and yelled at immediately.” The device worked, with all the bears receiving a shot from the device leaving the scene. Some of the bears only retreated a distance, but none returned for more. And the biggest of the bears completely fled the scene.

  The article quoted biologist Phil Mooney: “Mentally, I think it messes with the big bears much more.” The article noted the ECD abruptly terminates the normal chain of posturing in a bear–human encounter and leaves the bear sprawling helpless on the ground. Of 110 brown bears shot by ECDs, 100 percent responded by fleeing the scene.

  The ECDs are credited with preventing the loss of nine bears at the hatchery in 2012—bears that otherwise would likely have been shot in defense of life and property.

  Smith, Herrero, and DeBruyn pointed out that, with the smaller overt-reaction distance at bear aggregation sites, “It is less likely a person will unintentionally trigger an aggressive response at aggregations.”

  They assert that “bear-to-bear habituation is primarily responsible for the tolerant demeanor bears often have toward one another, and this tolerance sets the stage for humans to commingle at close range without great risk.” This is the best explanation as to why Treadwell’s dangerous behavior was allowed to continue for so many years before his eventual demise. And it provides an indication as to why such behavior in an area like the backcountry of Yellowstone or Glacier National Parks would not be conducive to allowing people like Treadwell to survive close encounters with grizzlies.

  Supplemental Feeding

  Outside places with magnificent salmon-spawning runs like those described in Alaska, grizzlies are found at lower densities, with much larger overt-reaction distances. But the idea of increasing nutrients available to bears to draw them to feeding areas and away from people is an idea that is getting increased attention from bear managers across the large carnivore’s range.

  In the 1970s, Yellowstone grizzly researcher Frank C. Craighead Jr. noted that the earthen garbage dumps in Yellowstone had once served to zone grizzlies away from people during the busy summer tourist season, and suggested in his book, Track of the Grizzly, that managers should again consider “zoning grizzlies away from people by reestablishing one or more earth-filled dumps in isolated areas.”

  Craighead reported on his experimental use of baits to draw Yellowstone bears from the adjacent countryside, congregating them into a localized area. He reported that using elk carcasses to draw bears “was a proven and effective management tool for separating grizzlies and visitors, a function that had been performed by the dumps.”

  Alberta, Canada, wildlife officials already take part in an “intercept feeding program,” in which road-killed wildlife are collected and stored during the winter months, then airlifted via helicopter to planned locations within spring grizzly bear range. According to the Parks Canada website, the idea is to “intercept” bears by keeping them away from livestock during the spring, until other natural food sources are available. Waterton Lakes National Park also allows “intercept” or “diversionary” feeding sites within park boundaries. Officials note that carrion is never placed near hiking trails, roads, or areas of human developments.

  The International Association for Bear Research and Management (IBA) held a panel discussion on diversionary bear feeding that was summarized in its quarterly newsletter, International Bear News, in November 2011. Moderator Dave Garshelis of the Minnesota Department of Natural Resources noted some bear managers support diversionary feeding as a conflict-management tool.

  Minnesota black bear expert Lynn Rogers advocates bear feeding in certain cases, noting that in one experime
nt, fed bears avoided people when not being fed, avoided campgrounds located near feeding sites, were involved in fewer conflicts, and were less likely to be killed than bears that were not fed, according to the International Bear News account. The IBA newsletter noted that shortly after the conference, “some bears from the Minnesota community where they are fed began getting into trouble, approaching occupied cars in a state park, breaking into a house, and even swatting a person who was attempting to approach a feeder in his yard. In the later case, the person (who received facial lacerations from the incident) tried to cover up the episode to protect the bears from potential agency retribution.”

  Other feeding programs offered a mixture of results. An illegal feeding program in the Lake Tahoe area of California and Nevada was undertaken during a severe drought in 2007, hoping to reduce the number of conflicts involving black bears breaking into homes. The program, carried out by a local bear advocacy group, was in violation of California state law prohibiting the feeding of wild animals, but did result in luring the bears away from homes, and the break-ins stopped, according to International Bear News.

  Diversionary feeding near Aspen, Colorado, had less success. International Bear News reported that diversionary feeding “often cannot compete with original attractants, and sometimes increased local wildlife densities and conflicts.” Managers continue to debate the merits and trade-offs associated with the short-term potential for reducing conflicts between bears and humans versus long-term dependency on feeding.

  Future Management