in the Canadian
Rockies
Bears and
Habitat
Bears and
Roads
Bears and
Science
Bear — Human
Conflict
Bears and
People
Are bears dangerous to
people?
While it is true that bears have the
potential to be dangerous to humans and that a number of people in Canada
are injured by bears every year, in reality, the incidence of attacks
on humans is relatively rare. Recent research into bear attacks on humans
has addressed questions such as: determining rates of human injuries
inflicted by bears in different geographical or jurisdictional areas and
attempting to explain any differences in these rates; identifying
immediate and long-term circumstances which contribute to the risk of
attack; identifying and relating different behaviours of grizzly and black
bears with respect to bear attacks; and the potential application of such
information in “managing” people and bears to reduce the risk of
encounters and/or attack.
A bear attack
research update
Herrero and Higgins analyzed incidences of
human injuries inflicted by bears in Alberta and British Columbia (B.C.)
between 1960–1998 and 1960-1997 respectively. The following are selected
findings from their studies:
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according to Dr. Steve Herrero bear attacks are rare but obviously traumatic events. In all of North America there are an estimated 800,000 black bears and 60,000 grizzly bears. Each year people have millions of interactions with bears. A very small fraction of these results in human injury. During the decade of the 1990s bears fatally injured on average 3 people each year and seriously injured about 12.
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the percentage of serious/fatal injuries in Alberta that occurred inside National Parks (as opposed to on Alberta lands outside of National Parks) was disproportionate (high) to the relatively small numbers of bears in the parks.
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the probable explanation for the above findings is the very large number of visitors in bear habitat in Alberta National Parks, and the associated challenge of human food and garbage management.
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injury rates for backcountry visitors to the National Parks were significantly higher than for front-country visitors.
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black bears far outnumber grizzly bears in both provinces. Grizzlies, however, were responsible for a significantly greater percentage of serious/fatal injuries than were black bears.
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data demonstrate behavioural differences between the two species. For example, competition with hunters, often over carcasses, and adult females acting in defense of their cubs were commonly associated with grizzly attacks in B.C. No cases of either type were recorded for black bears.
(Herrero and Higgins In PressA and Herrero and Higgins In PressB)
Are people dangerous to bears?
Grizzly bear mortality research
An
analysis of known grizzly bear mortalities in the Central Rockies
Ecosystem between 1971-1996 illustrates some of the ways, and the extent
to which, humans influence grizzly bear deaths in this area.
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627 of 639 known deaths were human-caused
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85% of 462 human-caused deaths with known locations occurred within 500m of a road or development, or within 200m of a trail
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in the National Park study area (Banff, Kootenay and Yoho National Parks), there were 118 recorded human-caused deaths. Problem wildlife control accounted for 72% of these, followed by highway and railway at 19%
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in the East Kootenay study area between 1976-1996, 81% of 319 recorded human-caused mortalities were the result of legal harvest
(Benn 1998)
A similar analysis that pooled radio-collared grizzly bear mortality data from studies in British Columbia, Alberta, Montana, Washington and Idaho, suggested that numbers of grizzly bear deaths are likely much higher than what is reported to management agencies. Their data show that without the advantage of radio-telemetry, management agencies would only have been aware of about half of the bear deaths. (McLellan et al 1999)
Black bear
mortality research
Information on black bear mortality in the
Canadian Rockies suggests cause for concern regarding the human influence
of roads and railways:
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between 1989-1999 vehicle-bear collisions were the highest cause of black bear mortality for bears in the Bow Valley area of Banff National Park. (Serrouya unpublished)
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the estimated maximum sustainable mortality rate for black bears in Banff is 15%; annual mortality rates for the years 1996-1999 were: 15%, 8%, 28% and 33% respectively. (Serrouya unpublished)
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a minimum of 30 black bears have been killed on the railway between Field and Revelstoke, British Columbia between 1993-1997; a minimum of 102 black bears have died on the Trans-Canada Highway in the same area between 1964-1997. (Munro 1999)
Causes and symptoms of bear-human conflict
Distinguishing between causes and
symptoms
In a review of literature
pertaining to bear-human conflict, Heuer emphasizes the distinction
between the causes and symptoms of conflict. Development in and
recreational use of bear habitat are the causes, and un-natural bear
behaviours – namely human habituation and human food-conditioning and
habituation – are the symptoms. (Heuer
1993) Misunderstanding of bear behaviour and biology, and the
lack of tolerance often exhibited by humans towards bears, may also be
considered causes of conflict. (British Columbia Conservation
Foundation 2000)
Human habituation and human-food conditioning
WHAT ARE THEY?
Bear researcher Dr.
Steven Herrero provides the following description of human habituation and
human food-conditioning in bears, and the circumstances that lead to these
behaviours:
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“If a bear regularly encounters quite a few people, but doesn’t get food from them and isn’t harmed, it simply gets used to people, will tolerate them at closer distances than before, and sometimes ignores them. Such a bear is habituated to people…
A habituated bear that also eats people’s food and garbage behaves differently than a bear that is only habituated. Such a bear forms a simple association –‘people’ may be followed by ‘food’. I refer to a bear with this expectation as being ‘food-conditioned’.” 2
WHAT ARE THE RISKS TO PEOPLE AND
BEARS?
Human
habituated and human food-conditioned bears are more likely to come into
conflict with people due to their increased proximity to, and associated
lack of wariness around, people. Such bears are therefore at greater risk
of removal or being killed as “problem wildlife”. They also have an
increased vulnerability to hunters, poachers and to becoming road-kill.
(Herrero 1985)
Human habituated bears and human food-conditioned bears have the potential to be especially dangerous to humans because:
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they are willing to be in close proximity to people, and in the case of food-conditioned bears, they may become bold in their attempts to secure food from people.
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people may mistakenly presume such bears to be “tame” and behave inappropriately around them.
Treating the causes of bear-human
conflict
Given that development and
recreational use in bear habitat have been identified as the causes of
bear-human conflict, preventing and/or reducing conflict necessarily means
managing human activity and behaviour. (Heuer
1993)
For example, the rate of serious/fatal injuries inflicted by bears on humans in the Canadian National Parks in Alberta declined with the implementation of careful food and garbage management in the mid-1980s. Most incidents between the 1950s and early 1980’s involved habituated and food-conditioned bears. (Herrero and Higgins In Press B)
Other means of managing human activity and behaviour include: seasonally restricting access into bear habitat, educating people who live, work and recreate in bear habitat as to correct behaviours and practices, and locating trails and facilities away from important bear areas.
Managing the symptoms of
bear-human conflict
Traditionally, dealing with
habituated or human food-conditioned bears, usually referred to as
“problem” bears, meant either: (1) killing the bear or (2) capturing it,
moving it to a different area within its home range (relocation) or
outside of its home range (translocation), and hoping that it would not
return and get into more trouble. While both types of actions are still
used, aversive conditioning is now also being employed in some
jurisdictions.
MEASURING SUCCESS
For a translocation
to be considered successful means much more than just that the bear has
not returned or gotten into trouble elsewhere. It requires that the
bear has adapted to its new surroundings, meaning:
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it has learned to forage successfully
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it does not get killed or displaced by resident bears
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it is able to reproduce successfully
(Ministry of Environment, Lands and Parks, British Columbia 1995)
Biologist Dr. Mike Gibeau points out that even if a translocation is “successful” according to these terms, it still results in a biological loss (mortality) to the population of origin. (Gibeau 2000)
There is evidence to suggest that “successful” translocations are in the minority.
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Kansas and Raine conducted a review of translocation studies and calculated a 60-70% return rate. They also found that offspring of the translocated individuals often had to be translocated themselves at least once in their lifetime. (Kansas and Raine 1987)
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the West Slopes Bear Research Project showed that the home range sizes of translocated female grizzly bears (~1 053 km2) are huge compared to non-translocated bears (~143 km2), and that translocated bears have the least predictable movements. These results suggest a compromised ability to efficiently utilize the landscape. (Woods et al 1997 and Woods 2001)
COSTS OF TRANSLOCATION
Translocation is expensive. It has been
estimated that each translocation in the province of British Columbia
costs a minimum of three Conservation Officer days, and ~$1800.00. If
helicopters are involved, the costs are substantially higher. (Ministry of Environment, Lands and Parks, British Columbia
1995)
Biologist Carrie Hunt notes that there are other costs incurred with translocation. Translocation sends a “false message” to the public who believe that something beneficial has been done for the bear. Translocation also tends to takes the focus away from the roots of the problem, such as the need to clean up potential attractants like food and garbage. (Wind River Bear Institute 2000)
Aversive conditioning
The basic
premise of aversive conditioning is that bears who have become habituated
to people, and/or human food-conditioned, can learn to change these
behaviours. This is achieved by creating a structured program wherein a
bear is monitored 24-hours a day for a period of time, and specific
lessons are taught and consistently reinforced. The lessons involve
teaching bears to associate “undesirable” activities (such as entering a
campground or remaining in the open when people are nearby) with negative
events, and “desirable” activities (such as leaving a campground or moving
into cover when people are nearby) with positive events.
“Negative events” include subjecting the bear to any of the following treatments, alone or in combination, while it is exhibiting the undesired behaviour (e.g., remaining in the open when people are nearby)
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being hit with rubber bullets or small bean bags
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sprayed with pepper spray
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loud noise from “screamers” or “bangers”
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yelling or barking and chasing by specially trained dogs
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“Positive events” means that as soon as the bear does what is desired (e.g., moves into cover) all of the above stops. The bear is left alone.
According to biologist Carrie Hunt, aversive conditioning conducted in this manner ensures that bears remain “flexible” – they know that they have options around humans and human-associated sites – rather than being instilled with a rigid fear response to people. Such a response could have tragic consequences if that bear later encounters people on a hiking trail or under circumstances where it feels threatened and unable to escape. It could also result in the bear being chronically stressed, especially if it’s home range is in an area of high human presence.
Aversive conditioning is time-consuming and expensive. However, when it is successful, it likely reduces long-term costs associated with dealing with a “problem bear”, and it keeps a bear alive that might otherwise have had to be killed.
(Source for all: Wind River Bear Institute 2000)