|
Introduction
Status and management of the brown bear in Alaska
Brown bear populations throughout most of Alaska are stable (Miller 1993). There are concerns, however, because Alaskan brown bears face many of the same intolerant attitudes and threats that have led to extirpation of the species throughout most of their historic range in the lower 48 states and Mexico. Advances during the 20th century in ecological consciousness, legal protection, wildlife management, and the existence of large reserves of public lands in Alaska, however, appear adequate to assure the survival of both subspecies in Alaska through the 21st century. Reductions in population density and extirpation in some localized areas will likely occur in portions of Alaska during this period.
Distribution and density of brown bears in Alaska
In southeastern Alaska, brown bears are abundant on Admiralty, Chichagof,
Baranof, and Kruzof Islands but are absent from the more southern
islands of Prince of Wales, Kupreanof, Etolin, and adjacent islands;
a few wandering brown bears are occasionally found on Mitkof and Wrangell
islands which are close to the mainland. In southeastern Alaska, black
bears (U. americanus) and The distribution of brown bears in Alaska appears to have remained relatively unchanged since European and Russian exploration during the mid-1700s (Figure 5.2). Brown bear densities vary greatly in different regions of Alaska. Density estimates conducted using standardized techniques (Miller et al. 1987) throughout Alaska reveal densities >175 bears/1,000km² in the coastal populations of the Alaska Peninsula, Kodiak and Afognak Islands, and the northern islands of southeastern Alaska (Figure 5.2) (Miller et al. in prep.). Approximately 50% of Alaska’s brown bear population occurs in these high density populations which represents about 8.5% of the brown bear habitat in the state (Figure 5.2). It appears likely that these high densities are supported in large part by abundant runs of up to five species of Pacific salmon (Oncorhynchus spp.) and lush plant and fruit resources found in these warmer maritime environments. Bears in these high density portions of the Alaskan coast are larger and generally darker than bears from interior and arctic regions of Alaska. These size and color differences have resulted in coastal bears being commonly called “brown” bears while the smaller and usually lighter-colored interior bears are called “grizzlies”. Densities less than 40 bears/1,000km² have been reliably estimated in the portions of interior Alaska without access to abundant salmon runs (Figure 5.2) (Miller et al. in prep.). These estimates range from 6.8/1,000km² on the coastal flatlands and adjacent foothills of the northeastern Brooks Range (Reynolds and Garner 1987) to 34 bears/ 1,000km² in Denali National Park (Dean 1987). These low density habitats represent about 84% of the brown bear’s distribution in Alaska (Figure 5.2). Approximately 41% of Alaska’s brown bear population lives in these low density habitats. Intermediate densities of 40–175 bears/1,000km² are thought to occur in small areas of south-central Alaska near the coast and on the mainland in southeastern Alaska. These areas represent approximately 7.5% of Alaska’s bear habitat and contain about 9% of the population (Figure 5.2). The classification of these areas as intermediate in density is based on subjective impressions; bear densities have not been directly measured in any of these areas. There is no precise estimate on the number of brown bears in Alaska.
During the period 1985–1992, however, information on brown bear
density was estimated in 15 Alaskan study areas using standardized
capture-mark-recapture techniques (Miller et al. in press).
Density estimates using other techniques were available in four other
areas (Miller et al. in press). In 1993, biologists from
Legal status In addition to sport hunting, brown bears may also be legally killed in defense of life or property. Persons killing bears under such circumstances are required to file a report with a state wildlife protection officer and to surrender the hide and skull to the state. Alaskan brown bears are on Appendix IIB of CITES. This listing is designed to protect threatened populations elsewhere in North America; the brown bear population status in Alaska is secure. Under this listing, a federal wildlife export permit is required before the hides or skulls of brown bears may be shipped out of the United States or transported through Canada. Until recently, the State of Alaska has had almost exclusive management authority for brown bears and other species of non-endangered resident wildlife in Alaska. However, under the subsistence provisions of the 1980 Alaska National Interest Lands Act (ANILCA), the US federal government in 1990 assumed management authority for subsistence uses of wildlife, including bears, for rural Alaskan residents on most federal public lands in Alaska (about 62% of the state). Uncertainties associated with the recent mixture of state and federal management authority have created administrative and legal problems that have and will continue to complicate efforts to manage harvests of bears and other species in Alaska.
Population threats Most hunting is for trophies but a small and underdocumented proportion
of the statewide hunting kill is for subsistence use by residents
in rural villages. An unknown, but perhaps significant, amount of
illegal killing also occurs throughout Alaska. Illegal kills occur
in National Parks and other closed areas as well as in areas open
to legal hunting. Although sale of bear parts is illegal in Alaska,
the increasing value of these parts in overseas markets has doubtless
resulted in an increased number of In a few management areas in south-central and eastcentral Alaska,
brown bear populations have been reduced through liberalized hunting
regulations designed to reduce bear numbers. Such reductions are desired
to increase moose (Alces alces) populations. Brown bears are
known to be effective predators on newborn moose (Ballard et al.
1981; Ballard and Larsen 1987; Ballard et al. 1990), but it
has not been demonstrated that these bear reductions have been successful
in improving moose calf survivorship (Miller and Ballard 1992). The
current areas where bears are being intentionally reduced are small
and the management objectives for these areas require maintenance
of “viable” bear populations. There is, however, widespread
and vocal support for proposals designed to reduce bear numbers in
many additional portions of Alaska (Miller and Ballard 1992). These
proposals reflect a willingness to reduce bear populations thought
to be too high for Unintended declines in bear populations as a result of sport hunting can best be avoided by establishment of conservative harvest quotas (Miller 1990). Even with conservative quotas, legal sport kills combined with inadequately documented kills in defense of life and property, subsistence kills, and illegal kills may significantly deplete populations. Declines from this combination of factors may be gradual and go undetected for long periods because available methods for direct monitoring of bear population trends are imprecise and expensive (Harris 1986; Miller 1990; Miller et al. in prep.). As human presence increases in once lightly occupied areas of bear habitat and in urban areas, killing of bears in defense of life or property has increased in Alaska (Miller and Chihuly 1987). Around urban centers and in heavily populated rural areas such as on the Kenai Peninsula, such kills are sufficiently frequent to have depleted local bear populations. The occasional human injury or death from bear attacks in Alaska increases fear of bears and these instances are usually followed by increased numbers of bears killed by persons who perceive bears as threats. Increased human presence and the commonly associated problem of bears being attracted to human foods and garbage increases the likelihood of damage to property or injury to people by bears (Herrero 1985). This pattern can initiate a cycle that may create population-level threats in large areas (Knight and Eberhardt 1988). With proper human behavior, education, and training, this cycle is not inevitable (Walker and Aumiller 1993; Aumiller and Matt 1994). The number of areas in Alaska where bear killing in defense of life and property will become significant sources of mortality will doubtless increase through the next century. This will lead to population reductions in additional localized areas and may reduce bear populations more widely in some important portions of Alaska.
Habitat threats Throughout the coastal rainforests of southeastern Alaska, industrial-scale logging on private and national forest lands is expected to significantly reduce brown bear habitat capability as important old-growth forest habitats are converted to second-growth plantations that are of limited value to bears and many other species (Schoen et al. 1994). Throughout much of this area, the timber harvests are concentrated in the highest-quality timber stands found in southeastern Alaska (Schoen et al. 1988). These stands are used extensively by brown bears during summer and have been identified as critical brown bear habitats (Schoen and Beier 1990). The impacts of this logging will be long-term and irreversible under current logging schemes. In addition, logging may reduce the long-term productivity of some of the region’s important salmon spawning streams which would have obvious implications for bears. In most of the rest of Alaska, brown bear habitat is still relatively
intact and there does not appear to be a serious threat of losing
significant habitat over the next 25 to 50 years. Although Alaska
may not face the same level of habitat loss that has occurred throughout
brown bear range in the lower 48 states, the suitability of bear habitat
must incorporate the influence of human activities (Schoen 1990).
Habitat fragmentation, roads, and garbage disposal are part of the
infrastructure of resource development (logging, mining, petroleum
development, hydropower development, agriculture, commercial and residential
real estate development) that, along with tourism, is the major emphasis
in Alaska’s growing economy. These factors contribute significantly
to direct mortality of brown bears
Management Except for rural subsistence bear hunters in northwestern Alaska, hunters are required to purchase a license and big game tag to hunt bears, and successful hunters are required to have the hide and skull of their kills examined and sealed by a representative of the Alaska Department of Fish and Game. During this examination, the sex of the kill is determined from the hide and a tooth is extracted from the skull to determine age by counting cementum annuli. Sport hunters may not take a bear more frequently than once every four years in most of Alaska. Compliance with kill reporting requirements is considered high in most areas of the state, but kills are underreported by hunters in many rural areas. Liberalized bag limits (1/ year), elimination of the need to purchase a tag, and easier reporting mechanisms have been instituted in portions of rural northwestern Alaska in an effort to increase voluntary reporting of brown bear kills.
The most popular brown bear hunting areas in Alaska are the Kodiak
Archipelago, Alaska Peninsula, and northern islands of southeastern
Alaska (Admiralty, Baranof, and Chichagof). In the Kodiak area, harvests
have been limited by means of a lottery for hunting permits since
1976. On the Alaska Peninsula, harvest has been limited by closure
of the area to bear hunting during alternate regulatory years since
1975. Together, 37% of the Alaska brown bear harvest derives from
Kodiak and the Alaska Peninsula. An additional 10% of the harvest
comes from high density populations on Admiralty, Chichagof and Baranof
islands. Statewide, over half of the annual harvest comes from the Several areas in Alaska are also managed to provide enhanced opportunities for brown bear viewing. These include the McNeil River State Game Sanctuary, Denali and Katmai National Parks, O’Malley Creek on Kodiak Island, and the Stan Price State Wildlife Sanctuary on Admiralty Island. Anan Creek on the mainland in southeastern Alaska is being developed for black bear viewing. Public demand for bear viewing opportunities is higher than can be sustained without adversely impacting bears and the quality of viewing opportunities. Thus, human use is limited in some sites by access permits. As the tourism industry continues to expand in Alaska, public demand will likely grow for creating additional bear viewing sites.
Human-bear interactions As human populations expand and demand for resources increases throughout the industrial world, more pressure is placed on Alaska’s natural resources. Today, resource extraction and tourism are the major industries shaping Alaska’s economy. Major resource developments in Alaska include fishing, oil and gas development, logging, mining, agriculture, road and rail construction, real estate development, mariculture and aquaculture, and hydroelectric development. Logging, oil and gas development, and mining all require an extensive transportation infrastructure. This fragments previously inaccessible or lightly inhabited areas of bear habitat and increases opportunities for legal hunting as well as for adverse bear-human interactions including defense of life and property kills and illegal hunting. A direct correlation was found between autumn brown bear kill and cumulative kilometers of road construction on northeastern Chichagof Island during the period 1978 to 1989 (Titus and Beier 1991). Outside of Alaska’s major urban centers, the two regions most
vulnerable to habitat fragmentation are the south coastal forests
which are being extensively logged and the North Slope. Over the long-term,
the transportation infrastructure will significantly increase the
probability that individual bear home ranges will be bisected by a
road or utility corridor. Increased human access inevitably Another byproduct of development is garbage. Garbage dumps associated with mining, logging, petroleum development, and local communities have been an attractant for bears and resulted in significant bear problems throughout Alaska. Bears that become conditioned to humans and human foods usually become nuisances and may become threats to human safety (Herrero 1985). The usual result is that such bears are commonly killed. Such attractant sites end up as “population sinks” where bears are drained from ecosystems (Knight et al. 1988). Although agriculture does not pose a serious threat to loss of bear habitat in Alaska, the livestock industry has the potential to significantly reduce bear populations through killing of bears seen as economic threats to livestock herders. Currently, the most significant threats derive from cattle ranchers on Kodiak Island and reindeer (Rangifer tarandus) herders in northwestern Alaska. Additional threats to bears would develop if schemes to develop moose or pig farming or to expand the area involved with reindeer ranching succeed. Fish hatcheries and mariculture facilities developed within high-density coastal brown bear habitat are also potential sites of conflict. If human garbage, hatchery stock, and fish foods are not handled and secured properly, they may attract bears from long distances. As these facilities proliferate along the coast, a significant proportion of bears may be vulnerable to nuisance control actions. Although most of Alaska’s lands are public lands, parcels of lands selected by the State of Alaska have been widely converted to small privately owned plots. Many Alaskans have built recreational cabins on these plots in areas where there was previously little human presence or construction. Many of the persons using these cabins view bears as a threat to their personal safety and are angered by damage bears cause to their structures. There are currently places in the state where complaints from owners of these remote cabins have led to efforts to reduce bear numbers through increased hunting. It is probable that owners of these cabins also shoot many bears that are not reported as required by law. In some places, lands transferred to corporations of Alaskan natives under terms of the Alaska Native Claims Settlement Act have similarly been developed for maximum economic returns with corresponding losses to bear numbers and habitats. Alaska’s wilderness character has attracted adventurous travelers
for more than a century but until
Public education needs
Conservation recommendations 2. Quantify how human presence affects brown bear habitat use and population viability.
Monitoring
Inventory
Gap analysis
Education
Policy
Planning
Law enforcement
Ecotourism
Conclusion
Acknowledgments
Status and management of the brown
bear in Canada
Figure 5.3. The distribution and status of brown bears (Ursus arctos) in Canada.
Population status and growing threats Estimating bear numbers is notoriously difficult. Without an intensive marking program, only estimations based on largely subjective information and extrapolation from research areas are available (Table 5.3). Banci (1991) estimated that about 25,000 brown bears live in Canada and this number has unlikely changed significantly in the past few years. In two of the brown bear zones, the Non-Mountainous Boreal Plains and the Glaciated Prairies, brown bear have been extirpated. In the Hot Dry Plateaus, brown bears are rare and considered threatened. The status of brown bears in the remaining zones are often debated; some people suggest that they are vulnerable while others believe they are doing fine.
Arctic Coastal Plains: An estimated 2,860 brown bears occur in this zone. Although there have been some sightings on Banks and Victoria Island, these bears are mostly limited to the mainland. This zone is sparsely populated by people and there is little road access. Impacts on bears occur near settlements and petroleum exploration and development have had a significant impact in localized areas. Over most of the area, brown bears are likely near carrying capacity. Taiga Shield: The status of brown bears in this region is poorly known but an estimate of 790 was provided by Banci (1991). The bear habitat is thought to be relatively poor on the Taiga Shield. There are no known recent records of brown bears from northern Manitoba or Saskatchewan. This zone has few human residents and bear kills are rare. Taiga Plains: The bear habitat in this zone is also inferior and, although density estimates are poor, a total population of 1,520 bears has been estimated. This zone has few residents and access remains poor. Subarctic Mountains: There are an estimated 2,540 brown bears in the Subarctic Mountains and this population has been hunted since 1965. The productivity of the population is low and hunting regulations are consequently strict. Access is limited in the zone and there are few human settlements. Subarctic Mountains and Plains: The density of brown bears in this zone appears higher than the more northern and eastern areas. A total of 5,680 bears are estimated to live here. There are three major highways crossing this area and there are a few communities with more than 2,000 people. Poor garbage management has resulted in bear deaths and many translocations. Mining and petroleum are the major industries in this zone. Hunting mortality associated with big game guiding is the major source of bear mortality. Cold Boreal Plains: Agricultural development has eliminated brown bears from a portion of this zone, however, an estimated 970 bears remain. Natural gas development is the major industry although the amount of forestry, in particular pulp production, is rapidly increasing. Access developed by the various industries is becoming a significant problem for brown bears. Human settlements are rare; however, there are three communities with over 4,000 people. Cold Moist Mountains: This zone is relatively good bear habitat and has an estimated population size of 2,940 brown bears. Forestry, mining, and big game hunting are the major industries. Human settlements are rare and small in this zone and although access is currently limited, it is rapidly increasing in certain locations. Temperate Wet Mountains: Some of the most productive brown bear habitat in the country occurs here. Vancouver, the largest city in western Canada, is located in the southern tip of this zone and the influence of such a large settlement has greatly affected brown bear numbers in this corner of the country. The southern coast supports about 90 brown bears which is only 5% of its estimated capability. There are few settlements in the north coast and access is generally difficult. Range fragmentation is a concern in the southern portion. Poor management of garbage and other attractants has resulted in bear deaths and many translocations. Although timber harvest and trophy hunting are very extensive in the north coast, an estimated 3,210 brown bears inhabit the area. Cool Moist Plateaus: Cattle ranching is extensive in portions of this zone and intolerance of large carnivores has significantly impacted brown bear numbers. Due to the generally flat topography, timber harvest is highly mechanistic and extensive. There are several large and many small communities in this zone and road access is extensive. Poor management of garbage and other attractants has resulted in bear deaths and many translocations. The estimated number of bears in this zone is 1,100. Cool Moist Mountains: This zone has some very productive bear habitat but there is also much rock and ice. A variety of human activities and in particular forestry, hydroelectric developments, and hunting have had a significant impact on bears in this area. Range fragmentation is a concern along transportation corridors. There are several towns of between 5–20,000 people and access is extensive. Poor management of garbage and other attractants has resulted in bear deaths and many translocations. Banff, Jasper, Glacier, and Mt. Revelstoke NPs are in this zone and although some very productive habitat occurs in these parks, as a whole, they are relatively poor for bears and support only about 250 of the estimated 2,540 brown bears in this zone. Hot Dry Plateaus: For brown bears, this is a relatively unproductive zone and, when combined with extensive areas of human settlement, agriculture, forestry, mining, recreation, and extensive access, only about 140 brown bears remain. Most of these bears occur along the border of the Wet Temperate and Cool Moist Mountains. Range fragmentation is a serious concern. Cool Dry Mountains: This zone has some very productive brown bear habitat but poor habitat is also common. Human activities are varied and brown bears have been impacted by agriculture, forestry, mining, hunting, and recreation. There are numerous small communities, and several with more than 5,000 people. Poor management of garbage and other attractants has resulted in bear deaths and many translocations. Access is widespread. Range fragmentation is a serious concern. There are an estimated 930 brown bears in this zone.
Legal status and hunting
Public education needs 1. Status: The variability of brown bears status should be stressed. The public should know that in some areas of relatively dense human rural and urban settlement, brown bears are threatened or have been extirpated while over much of their range populations remain healthy. 2. Hunting: The high natural adult survivorship and the variability of brown bear reproductive potential in various habitats and resulting variability in sustainable harvest levels should be stressed. In some areas, any harvest is likely unacceptable whereas in most areas, some hunting is ecologically sustainable. Whether society continues to support the hunting of brown bears due to ethical issues must be addressed from a neutral viewpoint. 3. Protected areas: The public should know that over 95% of the brown bears in Canada live outside National Parks and thus management actions outside protected areas are important influences on their viability. 4. Range fragmentation: The importance of connected bear range should be stressed. Habitats, even if they contain few bears but are located between areas with many bears, are very important and should be managed accordingly. 5. Vehicular access: The public should be aware of how important access management plans are to the long-term viability of brown bears as well as other wildland values. 6. The value of brown bears: People should be aware of the value of bears as a trophy to hunters, viewers, and photographers, plus as a wilderness symbol to tourists. They should also be aware of the potential value of bears to medical research. 7. Human impacts: Relationships between resource development, agriculture, and human settlement on brown bear habitat and populations should be clarified.
In addition, people that recreate, work, or live in brown bear habitat should receive information on: 1. How to camp and hike in brown bear habitat: The public should be informed how rare bear attacks are but at the same time learn how to act in bear country to avoid close encounters and what to do if a bear is encountered at close distance. Pamphlets and books are available and some suggestions are provided to people visiting National and Provincial Parks, but outside of parks, little information is available. 2. How to operate industrial camps in bear habitat: Over the past decade, major progress has been made towards reducing the impact of industrial camps on bears. Increased education for smaller businesses such as silviculture companies, smaller prospecting companies, and individual workers is still needed in most areas. A program to inform forestry workers and mineral exploration crews on bear safety would be beneficial in many locations. 3. How to live in brown bear habitat: Municipalities in bear habitat and the residents of these communities should be informed how to manage bear attractants such as garbage, fruit trees, aviaries, compost piles, livestock, and pet food. The lack of education for this group of people is a major shortcoming of current bear management in many locations.
Specific conservation recommendations
Habitat 1. 1:500,000 Scale: Because viable populations of brown bears require large areas, maintaining sufficient connected habitat will require land use planning at the 1:500,000 scale. Such a land-use plan is being developed in British Columbia. While maintaining viable brown bear populations may not require additional large protected areas, some key areas may need protection while many others may require special management consideration. In particular, human settlement and ranching must be limited in areas with important bear populations. Potential fracture zones between subpopulations will be identified at this scale. 2. 1:20,000 to 1:50,000 Scale: Land-use planning at the 1:20,000 scale will ensure an appropriate juxtaposition of habitat conditions through time. Planning linkages through fracture zones will also occur at the 1:20,000 scale. This scale of management is needed mostly where grizzly bear habitat is managed, particularly by the timber industry. 3. 1:2,000 Scale: Maintaining habitat in suitable condition for a period of time will involve stand-level plans at 1:2,000 in areas with exceptionally high habitat capability. This level of planning is needed mostly where there are resource use conflicts. Mortality 1. Legal harvest: Some harvest from many populations is sustainable, however, because censusing brown bears in most areas is not yet economically practical, setting appropriate harvest levels is problematic. Brown bears have a relatively low reproductive rate so are susceptible to overharvest and, if overharvested, are slow to recover. Consequently, harvest rates should be conservative and the responsibility should be on the resource user to demonstrate that harvests can be increased. Intentional bear reduction programs by direct removal or increased legal harvest designed to stimulate ungulate population growth must be undertaken with accurate monitoring. Legal harvest is the only form of mortality that is relatively easy to modify. 2. Problem animal removal: Problem animal translocation and killing is common near several communities and in some remote camps. Poor garbage management is the dominant problem, although other sources of attractants such as fruit trees, compost piles, aviaries, livestock, and inappropriately cleaned and stored fish and game are also problem sources. Programs to remove attractants by relocating or fencing dumps and educating the public are being implemented. 3. Defense of life and property: As is the case with problem animal removals, defense of life and property killings can be minimized by proper management of personal attractants, particularly at remote hunting, fishing, or small industrial camps. Education programs and guidelines for fish and game cleaning and storage and garbage management are needed. 4. Illegal killing: Illegal killing of brown bears is often related to improper management of personal attractants at hunting and fishing camps and rural residences. This form of illegal killing can be reduced by education and camp management guidelines. Active poaching of brown bears is more difficult to manage but levels can be reduced by making it more difficult to use the carcass or market animal parts. Access management will also reduce or at least localize illegal killing.
Status and management of the grizzly bear in the
lower 48 United States
Historic range and current distribution Grizzly bears occupied a variety of habitats prior to the attempted
extermination by Europeans. Grizzlies were found across the great
plains east of the Rocky Mountains where they were dependent upon
the millions of bison (Bison bison) that inhabited the prairies.
Early accounts (DeVoto 1953) remark on the abundance of grizzly bears
along the Missouri River in present-day Montana, USA. These bears
were apparently attracted to the river by hundreds of drowned bison
carcasses and the riparian zone foods such as shrubs. These carcasses
resulted from mass drowning when hundreds of thousands of bison crossed
the river. The grizzly was also distributed across the Rocky Mountains
from northern areas in Montana and Idaho (Moore 1996) south to Arizona
and New By the 1920s and 1930s, only 100 years after the arrival of European settlers, grizzly bears were being driven to extinction throughout much of their range. At this time, domestic sheep were a large agricultural interest that spread far into the mountains in the last refuges of the grizzly bear. Places that are now wilderness such as areas of the Bob Marshall and Scapegoat Wilderness in Montana and the Selway-Bitterroot Wilderness in Idaho were filled with herds of domestic sheep. The maintenance of domestic sheep in areas with grizzly bears and wolves (Canis lupus) required predator control techniques such as trapping and poisoning. By 1922 the range had been dramatically reduced and grizzlies were only present in isolated mountain areas. This was a reduction of approximately 75% in less than 100 years. By 1922 the range of the grizzly was a series of isolated populations which, because of their isolation, were more vulnerable to extinction. The 1920s and 1930s saw the lowest numbers of grizzly bears surviving south of Canada. In portions of the present-day Sun River Game Preserve in Montana, a place now rich in grizzly bears, an entire summer of searching for bear tracks only turned up one or two. Hunting and killing of bears for protection of livestock continued into the 1970s. Of the 37 populations present in 1922, 31 were eliminated by 1975. By 1975 grizzlies had been reduced to 7–800 in less than 2% of the former range. Five separate populations remained in the four states of Wyoming, Montana, Idaho, and Washington (Figure 5.4, Table 5.6). The only refuge for grizzlies were the two National Parks, Yellowstone Park in Wyoming, Montana, and Idaho, and Glacier Park in Montana. Of these five populations, four were contiguous with larger populations across the Canadian border. It was thought in 1975 that grizzly bears still remained in the Bitterroot Mountains of Idaho and Montana. Investigations since 1975 have found no evidence that grizzly bears remain in this area. The last bear verified in the Bitterroots was in the early 1940s. In 1979 an adult female grizzly bear was killed by a hunter in the San Juan Mountains of southwest Colorado. This was the first grizzly bear seen in the area in decades. Following this find, two years of intensive research failed to document any verified evidence of grizzly bears in the San Juans. It seems likely that the bear killed by the hunter was the last remnant bear in this area more than 800 miles from the nearest existing grizzly bear population. The San Juan Mountains are remote and it is possible that a few remnant bears could exist for many years and escape detection, but the likelihood of a remaining population of bears is very low. In 1975 the grizzly was declared a threatened species in the lower
48 United States and came under the protection of the Endangered Species
Act. This listing brought attention to the habitat and population
management needs of this species. Research was initiated in areas
outside National Parks, actions that could impact habitat such as
timber harvest and road building were modified to minimize The current distribution of the grizzly bear in the states of Wyoming, Montana, Idaho and Washington is shown in Figure 5.4.
Status The intention of the grizzly bear recovery program is to expand the range of the grizzly as much as possible within the large blocks of publicly owned lands in the northern Rocky Mountains and the North Cascades. Plans are being considered to reintroduce the grizzly into the Bitterroot Mountains. A program is ongoing to evaluate the linkage zones with the intention of maintaining the opportunity for reconnection between existing populations (Servheen and Sandstrom 1995). The range of the grizzly population in the Yellowstone ecosystem is expanding as this population continues to increase. The result is that the range of the grizzly bear may expand around, and possibly between, some of the existing populations.
Legal status
Population threats The sustainable level of human-caused mortality is an important parameter that can be used to judge the impact of existing mortality rates. The rate that is assumed to be sustainable for a population of several hundred bears, based on the work of Harris (1986), is no more than 6% human-caused mortality. However, this is the total and not the known rate. It is assumed that the known rate is 50%–66% of the total mortality rate (USFWS 1993; R. Mace unpubl. data). The exact difference between the known and total human-caused mortality rate is a matter of constant debate and is important because the sustainable mortality level is critical to population recovery. In order to assure that this rate is conservative, it is calculated on a minimum population size based on the number of females with cubs seen and reported to managers, and the goal of the recovery programs is zero human-caused mortalities. Even so, the calculation of this mortality rate continues to be a source of controversy.
Habitat threats Roads have two major effects on bears: 1) increased mortality risk for those bears using roaded areas, and 2) loss of habitat for those bears that avoid roads. A new Geographic Information System (GIS) analysis technique called the moving window technique allows us to monitor the spatial distribution of road density. Through this GIS approach and the innovative research approaches in Mace and Waller (1997) we now realize that grizzly bears use habitats less than expected where forest road densities are high. Closure of existing roads and prevention of unnecessary new road building in grizzly bear habitat is one of the most important tools we can use to improve grizzly bear habitat. Continued recovery program efforts have limited new road development in forested areas and have initiated road closure and reclamation programs that have reduced road density in many areas. Pressure for road access continues, however, and it requires continued efforts to assure habitat security. Private land development is one of the major threats to grizzly bears in the Rocky Mountains. Continual increases in numbers of human developments eliminate seasonal habitats from bear use. This is especially important in valley bottoms where most private lands are and which are also important spring habitat. Efforts to limit this development of private lands can only be successful by developing partnerships with local residents and their voluntary acceptance of lifestyles that have minimal impact on wildlife. Habitat fragmentation is a major threat to grizzly bears as lands between existing populations are developed, usually by private owners. Habitat fragmentation is also occurring inside existing population areas due to private land development. High-speed highways are continually being upgraded to accommodate higher traffic volumes. As this is done, it makes these highways wider, with higher traffic volumes and usually less vegetative cover nearby. All these factors make highways effective habitat dividers.
Management
Human-bear interactions Few of the over 550 grizzly bears that have been captured and radio-tracked have died naturally. Most of these grizzly bear deaths are due to humans. Causes of death include management removal of repeat problem bears, illegal kills, self-defense by people who are threatened by bears, auto and train collisions, and mistaken identity kills by black bear (U. americanus) hunters.
Public education needs Further public education work is needed on private lands where the behavior of residents and people newly arrived to rural areas may determine the death or survival of resident bears. Some success has occurred with local communities by developing a sense of ownership in maintaining grizzly bears through local community planning (Pelletier 1996). To gain local community support, however, requires intense effort with community members in building trust, an effort that must be repeated in each community. There must be recognition that such local community conservation efforts are a vital part of any bear conservation effort so that resources are available to complete such programs.
Specific conservation recommendations 1. Testing the linkage zone prediction model’s ability to predict the distribution of bears in relation to human activities, and the differential mortality related to occupancy around human use areas versus more remote areas; refining, if necessary, the assigned influence zones and scoring system based on this test; 2. Documenting effects of high-speed highways on bear habitat use and movements, and developing design guidelines to minimize detrimental effects of highways on bears and other large carnivores; 3. Documenting infection rate, distribution, and a possible cure for white-pine blister rust (Cronartium ribicola) on whitebark pine (Pinus albicaulis) in the Yellowstone ecosystem because whitebark pine cones are a major grizzly bear food; and 4. Improving comparative monitoring systems to assess productivity of major foods within and between all ecosystems.
Management needs include: 1. Monitoring female survivorship and reproductive rates in the Northern Continental Divide Ecosystem, Cabinet-Yaak, and Selkirk recovery areas to calculate population rate of change with a confidence interval; 2. Reintroducing grizzly bears into the Bitterroot recovery area; 3. Placing additional bears into the Cabinet-Yaak recovery area; 4. Completion of the access management task force recommendations for all recovery areas to assure habitat security and adequate road management; 5. Initiating public outreach and a process to augment the population in the North Cascades recovery area; 6. Improving public relations, including information and education involving local people in ownership of recovery, and targeting special groups such as backcountry users and new residents in spring habitats for increased outreach efforts; 7. Completing the linkage zone analysis between all recovery areas and implementing necessary management actions in areas where linkage opportunities exist; 8. Assisting in the development of locally-developed land management recommendations by private landowners in grizzly habitat so people can learn to live in such areas with limited effect on bears; 9. Establishing improved cross-border management planning with Canada; and 10. Improving easement actions to assure maintenance of grizzly habitat on private lands subject to development. |
