Taking the phrase “Roadside Bear” to another level: Asphalt Bear - The Journey of 863 through the Greater Yellowstone Ecosystem
The journey of grizzly 863 begins in Muddy Creek, Shoshone National Forest (SNF). In 2015, as a recently booted 2-year-old subadult, 863 was captured July 25, for management purposes with her (potential) sibling, for repeated conflicts and habituation (frequenting developed areas). They both were transported to Bailey Creek, Bridger Teton National Forest (BTNF) (personal communication WYGF). Almost one year later, July 17, 2016, grizzly 863 was captured at Blackrock Creek, BTNF. She is currently radio collared. She was observed with no cubs during 2016. The following year in 2017, again, grizzly 863 at now 4-years-old, was observed with no cubs.
In 2019, she was first observed May 6 with 2-cubs-of-the-year (COY).
Many of the first observers were alarmed by 863’s actions and behavior. Initially, on May 6, 2019, she was observed rolling around in a fresh patch of asphalt on HWY 26. She was covered in the black tar like substance, and her young stood nearby, probably wondering if their mother bear was crazy. Oil and petroleum products, whether refined, or derivatives, attract grizzly bears. Fuel by itself is considered an attractant for bears.
Case: During a 15-year provincial project in Alberta, Andrea Morehouse, a wildlife biologist with the University of Alberta, came across an interesting observation. The goal of the project was to reduce spring incidents of grizzlies killing cattle. In an effort to alter and mitigate that behavior, roadkill were collected and dropped at remote locations. Morehouse wanted to document how many unique bears were using the remote carcass sites. At each remote location, roadkill would be positioned and then two trees near the area would be sprayed with WD-40 and wrapped in barb wire; WD-40 elicits a rub response from bears so they would come to the sites, eat and then rub on the trees.
It is likely that the combination of aliphatic hydrocarbons, petroleum bases/derivatives is what intrigues bears and elicits a behavioral (rub) response. This probably serves as the most likely reason that grizzly 863 was rolling in freshly patched asphalt. So to answer the cubs: no your mother bear is not crazy, just being a bear.
Roadside Bears: Habituation tolerance
Grizzly 863 has taken up a similar strategy that has been observed in many females with cubs: raising them in close proximity to the roadside. Now whether that is to provide security, we cannot prove; it is very much a double edged sword. Most bears observed near roads during spring are foraging on natural food sources. Late spring and early summer coincide with seasons when food productivity near roadways is rated higher than that further away from roadways (Mattson et al. 1987). All classes of bears use roadside habitats, not just classes which are subordinate or even security conscious (Haroldson & Gunther 2013). During mid-May, grizzly 863 was observed being pursued and chased by other bears. Shortly thereafter, she was observed with only one remaining cub.
It is important to understand that while bears may select roadside habitats during the spring because of their high productivity as opposed to habitat further away from roadways, it is not acceptable or appropriate for a grizzly or family group to linger in the roadway. The National Park Service since 1990, has instituted the bear management strategy of habituation tolerance. This strategy has been in place for nearly 30 years (1990-2019). The main priority of staff dispatched to bear jams, or roadside bear events, is to ensure public safety. This includes ensuring vehicles are parked legally, visitors are behaving in an appropriate manner, and not creating an unsafe or unpredictable situation by approaching, harassing or feeding bears present (Gunther et al. 2015).
It is important to consider the differences between national parks, national forests, and the surrounding adjacent communities. Each group does not manage wildlife (bears) in the same manner or have the same objectives. While the national parks between Yellowstone and Grand Teton have adopted the strategy of habituated tolerance, this strategy is not feasible in local communities and contrary to the missions or objectives set forth by other agencies.
Aversive Conditioning and Hazing as Management & Safety Tools
Hazing of bears in Yellowstone and other areas of the Greater Yellowstone comes in the form of bear deterrent round, thumper gun projectiles, sling shots, rocks, cracker shells, sirens, horns in an effort to temporarily move bears away from roadsides, human occupied areas, or where there is a bear-related safety concern.
Aversive conditioning is a form of learning which takes place when an animal is punished for an undesirable behavior. The goals of aversive conditioning are the following (Gunther 1994):
Specific guidelines have been established for when to use aversive conditioning which include (Gunther 1994):
The Take Home Message:
It is important to recognize the significance of roadside habitat for bears of all cohorts. However, we must respect that significance and allow for bears to behave in as much of a natural manner as possible, undisturbed by our actions. Our presence alone is something many bears such as 863, have grown to tolerate. We should not take their tolerance for granted; behavior is not a sound science, and grizzly bears are wild. Success breeds complacency; complacency breeds failure. Becoming complacent while viewing roadside bears is ultimately what may lead to the downfall of a nearly three decade old management strategy.
1.) Gunther, K. A. (1994). Bear management in Yellowstone National Park, 1960-93. Bears: their biology and management, 549-560.
2.) Gunther, K. A. (1994). Yellowstone National Park Bear Management Plan. National Park Service, Yellowstone National Park. pp. 66.
3.) Gunther, K. A., Wilmot, K. R., Cain, S. L., Wyman, T., Reinertson, E. G., Bramblett, A. M. (2015). Habituated grizzly bears: a natural response to increasing visitation in Yellowstone and Grand Teton National Parks. Yellowstone Science, 23, 33-40.
4.) Haroldson, M.A., Gunther, K. A. (2013). Roadside bear viewing opportunities in Yellowstone National Park: characteristics, trends, and influence of whitebark pine. Ursus, 24(1), 27-42.
5.) Mattson, D. J., Knight, R. R., Blanchard, B. M., (1987). The effects of developments and primary roads on grizzly bear habitat use in Yellowstone National Park, Wyoming. International Conference on Bear Research and Management 7:259–273.
Tyler Brasington is a native born and raised Pennsylvanian, yet proud current Wisconsin resident. He graduated from the University of Wisconsin-Whitewater with a B.S. in Environmental Science. Currently, Tyler is pursuing his masters in Natural Resources with the University of Wisconsin-Stevens Point. He has worked in Yellowstone National Park under the guidance and supervision of Dr. George Clokey and Dr. Jim Halfpenny.
Disclaimer: The information and views expressed on this page do not necessarily represent the views of the Department of Interior, US Geological Survey, National Park Service or the United States Government.
The Greater Yellowstone Grizzly Project
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