Grizzly bear (Ursus arctos) COSEWIC assessment and update update status report: chapter 6

6. Population size and trends

6.1 Introduction

Censusing grizzly bears is costly, difficult, and generally imprecise. Low sightability in most bear habitats precludes the use of direct-observation techniques such as aerial surveys. Sightability is better in tundra environments, but low bear densities in those areas render aerial surveys impractical. The most reliable and broadly used techniques employ invasive means including capture-mark-resight with or without radiotelemetry (Miller et al. 1987; 1997). 

Recent developments in population estimation techniques include camera traps, wherein bears trip cameras and photograph themselves (Mace et al. 1994). Most recently, DNA fingerprinting of hair follicles from bears attracted to baited barbed wire snags has been used to identify and count individuals and estimate densities (Woods et al. 1999; Mowat and Strobeck 2000). Each technique requires rigourous adherence to statistical protocols to avoid or minimize biases and errors associated with problems such as unequal probability of capture or resight, assumptions of population closure, and identification of the precision of estimates. 

In most reported Canadian studies, population estimates have been derived from a combination of capture data, telemetry data, and observation data. Most Canadian studies have required radiocollaring of bears to fulfil several additional project objectives, so derivation of population estimates using radiotracking data has been common. This approach is broadly applicable and broadly applied, but it frequently violates assumptions and usually provides no measure of precision (Mace et al. 1994). Furthermore, the high cost of estimating bear populations and the vastness of occupied grizzly bear range in Canada requires extrapolation of calculated densities across large areas of presumably similar habitat quality and bear density.

These difficulties lead to generally low precision in most estimates of grizzly bear population size. Consequently, most census data can only detect fairly drastic changes in abundance over time. No Canadian jurisdiction claims a high degree of confidence in either the precision or accuracy of their grizzly bear estimate.

This preamble is essential to qualify the data presented in this section. Data were provided to the author by senior bear management personnel from each jurisdiction, and represent the current state of knowledge within that jurisdiction, upon which bear management decisions are based. Estimates of bear density and population size were based primarily on field studies within portions of each jurisdiction (Table 5), and extrapolated to account for data gaps elsewhere. Because bear populations are estimated provincially or territorially, those estimates are provided based on jurisdictional boundaries. However, it is noted that these estimates do not refer to distinct bear subpopulations.

The Canada-wide grizzly bear population is estimated at 29 921, with an estimated range of 26 916 to 34 150 (Table 6). The point estimate represents an increase of 4781 (19%) from the 1990 estimate (Banci 1991). However, as noted in Table 6, higher estimates for most jurisdictions are related to changes in estimation methodology, reporting precision, and new data. Only Alberta reported an increased population, and that increase contributed only 290 bears. Over all of Canada, there is no evidence that the grizzly bear population size has changed since 1990. 

The lack of precision in grizzly bear population estimates strongly influences the Canada-wide status of the species. Current census techniques for grizzly bears are only now beginning to permit inventory of bear populations, and to provide reliable estimates of population size complete with confidence intervals. These techniques were not available even 10 years ago, making earlier estimates of bear populations little more than guesses, and certainly not directly comparable to current estimates. Therefore, it is not possible to evaluate trends in grizzly bear population size over any period beyond the past 10 years, aside from extrapolations based on changes in habitat availability.

Age structure in bear populations is influenced by population fecundity and by management regime to which the population is subjected (for example, cases where adult cohorts are selectively removed; Schwartz et al. in press). Bears of breeding age have been estimated to comprise from 25.6% to 59.0% of a grizzly bear population (Schwartz et al. in press). According to these values, and taking the point estimate, the breeding-age population in Canada is 6 891 - 15 881 bears. Using the high and low population range estimates, the number of breeding-age bears could range from 5 893 to 16 682.

 

Table 6. Estimated grizzly bear populations in Canada, 1991 and 2001/2002. Data from sources cited in text, except where noted.
Jurisdiction 1991Footnote a 2001/2002 Comments
PointFootnote b Range
Alberta (AB) 575 841 841 to 865 Estimated 46% increase since 1988 (3.9% annual increase).
British Columbia (BC) 13 000 at least 14 000 14 000+ Iterative estimation methodology. Change not believed to represent absolute change in population. Province-wide, trend considered to be stable.
Yukon 6 300 6 300 6 000 to 7 000 Territory-wide trend considered stable. Official estimate is 6 000 - 7 000.
Northwest Territories (NWT) 5 050 5 100 5 100 Does not imply population change. Land area and bear population of Nunavut excised in 1999, and estimation methodology revised to incorporate new data.
Nunavut n/aFootnote c 1 000 800 to 2 000 No official estimate available. Provided is a crude, unofficial estimate, determined from an estimated density of 4 bears/1 000 km2 for a 200 000 km2 portion of western and northern mainland Nunavut, plus an estimated density of 1 bear/1 000 km2 for a 20 000 km2 portion of eastern mainland Nunavut.
AB Natl. ParksFootnote d 215 180 175 to 185 Revised estimation methodology. No perceived change since 1991.
Total 25 140 at least 27 421 26 916+ to 29 150+ Changes in estimates between 1991 and 2001/2002 are largely due to revised methodology and new data. Overall, the Canada-wide trend between 1991 and 2001/2002 is perceived to have been stable.

6.2 Alberta

The total grizzly bear population on provincial lands in Alberta was estimated to be 841 in 2000 (Kansas 2002). In addition, about 175-185 bears are estimated to occur in Waterton Lakes, Banff, and Jasper National Parks for a province-wide total estimate of 1016-1026 bears.

Alberta is the only jurisdiction to report an increase in grizzly bear population over the period covered by this status report update. The estimated absolute increase on provincial lands of 46.3% equates to an average annual increase of 3.9%. National Park totals remained essentially stable during this period. The 1990 estimate for Banff National Park of 75 bears (Nagy and Gunson 1990) is within the current estimated range of 60-80 bears (Gibeau et al. 1996; Herrero et al. 2001).

About 154 000 – 200 000 km2 of provincial lands in Alberta are considered to be potential grizzly bear habitat (Nagy and Gunson 1990; Alberta Environmental Protection 1997). Although this is substantially reduced from historical levels (grizzlies formerly occupied virtually the entire province: 661 000 km2), this range reduction occurred primarily in the 1800s and early 1900s. Range contraction since 1990 has not been documented, although it may have occurred at local levels. Recolonization of historic ranges is suspected in some areas, especially the agricultural fringe along the eastern and northeastern boundaries of current distribution (H.D. Carr, pers. comm.).

Between 1981 and 1999, the numbers of males, females, and total bears in the Alberta grizzly harvest have declined (Table 7), most likely due to changes in management practices. Hunting regulations became increasingly restrictive over that period, including the implementation of limited-entry permits, closure of fall seasons, and prohibition of non-resident hunting. Annual numbers of bears killed by other man-caused means did not change, but the total of all recorded man-caused mortalities declined.

 

Table 7. Known man-caused grizzly bear mortalities in Alberta, 1981 to 1999.
Year Hunter killsFootnote a.1 Non-hunting man-caused Grand total
Males Females U/k sex Total Illegal DLPFootnote b.1 Other
1981 17 9 5 31 5 1 1 38
1982 15 14 0 29 7 6 1 43
1983 27 16 1 44 5 6 0 55
1984 26 20 0 46 1 4 1 52
1985 25 19 0 44 2 3 2 51
1986 31 14 0 45 2 0 1 48
1987 27 16 1 44 7 14 0 65
1988 7 1 0 8 1 5 1 15
1989 5 3 0 8 9 2 0 19
1990 13 8 0 21 9 1 0 31
1991 7 3 0 10 2 3 2 17
1992 19 3 0 22 3 4 1 30
1993 12 8 0 20 1 8 1 30
1994 4 3 0 7 5 3 1 16
1995 11 3 0 14 1 3 0 18
1996 13 7 1 21 3 5 0 29
1997 8 3 0 11 4 4 0 19
1998 6 8 0 14 3 6 1 24
1999 12 9 0 21 6 5 4 36
Total 285 167 8 460 76 83 17 636
Overall Mean 15.0 8.8   24.2 4.0 4.4 0.9 33.5
S.E. 2.0 1.4   3.2 0.6 0.7 0.2 3.5
1981-1989 Mean 20.0Footnote c.1 12.4Footnote c.1   33.2Footnote c.1 4.3 4.6   42.9Footnote c.1
S.E. 3.1 2.2   5.2 1.0 1.4   5.5
1990-1999 Mean 10.5Footnote c.1 5.5Footnote c.1   16.1Footnote c.1 3.7 4.2   25.0Footnote c.1
S.E. 1.4 0.8   1.8 0.8 0.6   2.2
P-value 0.0055 0.0038   0.0018       0.0026


Grizzly bear distribution in southern Alberta consists of a strip along the Continental Divide, in places narrowing to 30 km. This is contiguous with grizzly habitat on the BC side of the Divide, but even so remains constricted. The risk of population fracture along this strip, combined with relatively high mortality and control-removals of grizzlies from the southwestern corner of the province as a result of livestock depredation (Gunson 1995; H.D. Carr, pers. commun.), dictate a particular need for cautious management in this area.

A Population Viability Analysis (PVA) was conducted for the Central Rockies Ecosystem in Alberta and BC (Herrero et al. 2000). The model was based on assumptions for many input parameters, which were derived from science and which represented the best professional judgement of many of North America’s grizzly bear experts, but the reliability of the model’s predictions remains highly sensitive to even minor changes or errors in those assumptions. The model predicted that the grizzly bear population in that region is not presently secure. Increasing human population in the region was assumed (based on region-specific empirical data) to result in increased adult female grizzly mortality and/or decreased population fecundity. When projected increases in the human population were incorporated, the model predicted a rapid decline of the grizzly population. The model further predicted that goals of maintaining or increasing the population are unlikely to be met without strong mitigation efforts leading to a decrease in annual mortality. Consequently, even as the human population increases in the region, it will be essential to reduce human impacts on bears (Herrero et al. 2000).

6.3 British Columbia

The total grizzly bear population within British Columbia, including National Parks, was estimated at a minimum of 14 000 in 2002. This value is generally consistent with the provincial total estimated in 1991 (13 000 bears; Banci 1991). The current value arose from improved methodology and new data, as well as acknowledged uncertainty in the accuracy and precision of the estimate. The province-wide trend is considered to be generally stable, although declines in some areas and increases in others are suspected (T. Hamilton, pers. commun.). Grizzly bears along much of the southern fringe of their distribution in BC occur at low or very low densities, including in the Coast, Yahk, and South Selkirk Mountains (McLellan 1998). 

Grizzly bears currently occupy an estimated 750 000 km2 of British Columbia. Historically, about 917 000 km2 of mainland BC provided bear habitat. Most of this 18% range contraction occurred prior to 1960. However, current stresses on grizzly bear habitat and distribution in the province remain focused on the southern fringe. 

As reported in Section 2.3.1, at least 8 isolated grizzly bear populations have been identified in southern BC (Figure 11; McLellan 1998; T. Hamilton and B. McLellan, pers. commun.). Five of these occur within Grizzly Bear Population Units (GBPU) which have been designated by the province as Threatened. Status of these population isolates is summarized in Table 8. Each has been isolated primarily as a result of human developments and activities, which continue to threaten the persistence of the bear population within each area. Survival of these population units will depend on recognition of their isolation, and active measures to reduce mortality, conserve habitat, and restore connectivity.

 

Table 8. Summary of isolated grizzly bear population units in southern British Columbia. Data from T. Hamilton and B. McLellan (pers. commun.).
Unit name Estimated population Boundaries Specific Threats
Garibaldi-Pitt GBPUFootnote a.2 19 South: Lower Mainland; West: Pacific Ocean and BC Hwy 99; North: Duffy Lake Road and the parallel BC Hwy 99. Some connection may be possible across the Lillooet River and Harrison Lake to the Stein-Nahatalatch population (see below) but unlikely given low densities and degree of habitat alteration due to logging and agriculture and resulting high road densities and traffic volumes. Extensive logging, resulting in reduction of habitat suitability under closed canopy second growth stands; very high recreational and commercial tourism use. Few salmon spawning areas outside urban/rural areas, and low ungulate densities.
Squamish-Lillooet GBPU 27 East: BC Hwy 99; West and South: Pacific Ocean; North: the highly developed (settlement, logging, agriculture) Upper Lillooet Valley.  Expanding settlement; very high open-road densities with high traffic volumes; very high recreational and commercial tourism use. Extensive logging resulting in an overall lowering of habitat suitability under closed canopy second growth stands. Fire suppression has exacerbated this situation.
Stein-Nahatalatch GBPU 60 East: Fraser River, 2 national railways and the Trans-Canada Highway; South by the highly settled Fraser Valley; North by the Duffy Lake Road, and the parallel BC Hwy 99. There may be limited connection west to the Garabaldi-Pitt GBPU (see above) across Harrison Lake and the Lilooet River. Roads; logging; recreation; illegal mortality; potential conflict with cattle grazing; fire suppression. 
Marble/Pavillion Ranges Group <20 These bears are confined to an area south of Clinton, and east of Lillooet and the Fraser River.  There may be two groups of animals, one south and one north of Highway 12 through Pavillion. The area is extensively used for grazing, and is highly roaded with several settlements. These grizzly bears may represent the last group in Canada adapted to the extremely dry Southern Interior.
Sheep Ck/Rossland Group <20 Isolated to the South by the US (no bears), to the West by the densely-settled Okanagan valley and to the North by Hwy 3. The bear population North of Hwy 3 is also at a very low density, although it is more likely linked to populations to the north and east. Continued expansion of motorized access and settlement. Fire suppression has limited the amount of early seral (berry-producing) habitat and there is continued potential for conflict between livestock and bears.
Pennask Lake Group <10 Completely isolated by unsuitable habitat. Area is highly roaded and heavily used for public and commercial recreation. The area is “cottage country” with extensive logging roads throughout.
North Cascades GBPU <25 See text Section 2.3.1. See text Section 2.3.1.
South Selkirks GBPU 67 See text Section 2.3.2. See text Section 2.3.2.


From 1976-1989 to 1990-1999, the numbers of grizzly bears killed legally and illegally did not change significantly (Table 9). However, the number of bears reported to be killed in defence of life or property (DLP) nearly tripled over that interval.

Table 9. Known man-caused grizzly bear mortalities in BC, 1976 to 1999.
Year Hunter killsFootnote a.3 Non-hunting man-caused Total
Males Females Total Illegal DLPFootnote b.2 OtherFootnote c.2
1976 148 86 234 n/a n/a   234
1977 176 93 269 n/a 4   273
1978 226 78 304 n/a 6   310
1979 200 117 317 4 13   334
1980 249 116 365 7 19   391
1981 250 129 379 2 7   388
1982 215 112 327 7 16   350
1983 238 119 357 9 16   382
1984 240 125 365 9 16   390
1985 211 133 344 8 20   372
1986 223 120 343 8 14   365
1987 230 137 367 6 17   390
1988 190 121 311 7 17   335
1989 210 130 340 22 21   383
1990 200 111 311 10 15   336
1991 222 134 356 8 14   378
1992 240 116 356 9 28   393
1993 160 77 237 3 35   275
1994 181 99 280 4 38   322
1995 183 105 288 5 83   376
1996 224 139 363 8 32   403
1997 154 70 224 1 41   266
1998 140 70 210 4 35   249
1999 169 95 264 7 81   352
Total 4879 2632 7511 148 588 0 8247
Overall Mean 203.3 109.7 313.0 7.0 25.6   343.6
S.E. 6.8 4.4 10.5 0.9 4.3   10.4
1976-1989 Mean 214.7 115.4 330.1 8.1 14.3Footnote d.1   349.8
S.E. 7.7 4.8 10.9 1.5 1.5   13.0
1990-1999 Mean 187.3 101.6 288.9 5.9 40.2Footnote d.1   335.0
S.E. 10.5 7.8 17.9 0.9 7.5   17.6


The southern fringe of grizzly distribution in BC consists of at least 4 peninsular extensions (McLellan 1994). Dedicated effort will be required to prevent further constriction of those peninsulas, with subsequent fragmentation. The PVA model for the Central Rockies Ecosystem described above (Section 6.2) pertains to a portion of southeastern BC as well. Its dire predictions can only be mitigated by reversal of current trends in human population and activity in grizzly country.

6.4 Yukon

The Yukon Territory-wide estimate in 2000 is 6000 – 7000 grizzly bears. The estimate of 6300 reported by Banci (1991) is consistent with the current estimate and reflects changes in reporting precision rather than population size (J. Hechtel, pers. commun.). With local exceptions, the grizzly population in Yukon is considered to have remained stable since 1991.

Nearly all of the Yukon’s land mass (483 000 km2) is occupied by grizzly bears. No reduction in bear distribution has been documented in the Territory.

From the 1980s to the 1990s, the Yukon harvest of males, females, and all grizzly bears declined slightly (Table 10). Other man-caused mortalities remained constant, but the total man-caused mortalities declined.

6.5 Northwest Territories

Direct comparisons of grizzly bear population estimates and evaluation of trends in the Northwest Territories are complicated by changes in jurisdictional boundaries. Nunavut was declared as a distinct territory on 1 April 1999, including a substantial land mass and a grizzly bear population. The bear population in Nunavut is considered later.

Additional land-claim agreements include the establishment of the Inuvialuit Settlement Region, the Gwich’in Settlement Area, and the Sahtu Settlement Area. The Government of the Northwest Territories continues to manage wildlife within these settlement areas, but does so co-operatively with a variety of agencies and land-claim organizations.

The total grizzly bear population for the Northwest Territories is estimated at about 5 100 (Gau and Veitch 1999; Table 6), within an area of about 641 000 km2. After accounting for the removal of the bear population to what is now Nunavut, an increase is suggested since 1991. However, no data exist in support of either an increase or a decrease during that period. Official estimates of the grizzly bear population size had not been made previously. It is the opinion of regional wildlife managers that grizzly populations within the Northwest Territories have been essentially stable since 1991 (D. Cluff, J. Nagy, and A. Veitch, pers. commun.). There is no evidence of a change in distribution of the grizzly bear in the Northwest Territories since historic times (Schwartz et al. in press).

 

Table 10. Man-caused grizzly bear mortalities inYukon, 1980 to 1999. Records exclude the Inuvialuit Settlement Region and the Gwich'in Settlement Area.
Year Hunter killsFootnote a.4 DLPFootnote b.3 Other Grand total
Males Females U/k sex Total
1980 54 29 0 83 9 3 95
1981 58 26 1 85 6 3 94
1982 58 21 1 80 16 4 100
1983 46 28 1 75 8 2 85
1984 76 36 0 112 15 6 133
1985 59 37 1 97 17 3 117
1986 53 41 0 94 11 1 106
1987 85 41 0 126 20 1 147
1988 68 43 0 111 5 2 118
1989 57 34 0 91 14 1 106
1990 64 25 0 89 15 4 108
1991 44 33 0 77 6 4 87
1992 55 36 0 91 14 1 106
1993 44 27 0 71 13 0 84
1994 47 30 0 77 9 2 88
1995 37 26 0 63 18 0 81
1996 72 30 0 102 13 0 115
1997 58 29 0 87 22 1 110
1998 43 19 0 62 10 1 73
1999 46 20 0 66 12 2 80
Total 1124 611 4 1739 253 41 2033
Overall Mean 56.2 30.6 0.2 87.0 12.7 2.1 101.7
S.E. 2.7 1.6   3.8 1.1 0.4 4.2
1980-1989 Mean 61.4Footnote c.3 33.6Footnote c.3   95.4Footnote c.3 12.1 2.6 110.1Footnote c.3
S.E. 3.7 2.3   5.2 1.6 0.5 6.0
1990-1999 Mean 51.0Footnote c.3 27.5Footnote c.3   78.5Footnote c.3 13.2 1.5 93.2Footnote c.3
S.E. 3.5 1.7   4.2 1.4 0.5 4.7
P-value 0.0396 0.0387   0.0114     0.0272


Because of changes in jurisdictional boundaries, mortalities in Northwest Territories and Nunavut are considered jointly (Table 11). Hunter kills, DLP kills, and total mortalities fluctuated over the reporting period.

Table 11. Known man-caused grizzly bear mortalities in Northwest Territories Footnote a.5 and Nunavut, 1989 to 1999.
Year Hunter killsFootnote b.4 Non-hunting man-caused Grand total
Males Females U/k sex Total Illegal DLPFootnote c.4 Other
1990 5 3 0 8   8   16
1991 7 1 1 9   6   15
1992 10 1 0 11   5   16
1993 8 4 1 13   12   25
1994 14 1 1 16   13   29
1995 5 0 4 9   9   18
1996 12 3 1 16   4   20
1997 10 1 0 11   15   26
1998 5 1 2 8   15   23
1999 5 2 0 7   7   14
Total 81 17 10 108 0 94 0 202
Mean 8.1 1.7 1.0 10.8   9.4   20.2
S.E. 1.0 0.4 0.4 1.0   1.3   1.7
ISRFootnote a.5 Total
1990-1999
151 33 15 199   52   251
GSAFootnote a.5 Total
1990-1999
19 4 4 27   26   53
Grand Total 251 54 29 334 0 172 0 506
Grand Mean 25.1 5.4 2.9 33.4 0 17.2 0 50.6

6.6 Nunavut

Prior to 1 April 1999, the grizzly bear population in Nunavut existed in the Northwest Territories. Currently, no official population estimate for Nunavut exists. Grizzly bears occur within 2 regions: Kitikmeot and Kivalliq (formerly Keewatin). Densities within either region have not been estimated. However, in an attempt to develop a reasonable guess as to the number of bears within Nunavut, I extrapolated from empirical data collected in the closest proximity, in consultation with regional wildlife managers. It must be stressed that this exercise was completed in order to provide a working guess of population size, in recognition of the fact that grizzly bears do exist in Nunavut. It does not indicate a familiarity with the grizzly bear population or its habitat within Nunavut.

Grizzly bear density in the Brock-Hornaday Rivers area, immediately west of the NWT/Kitikmeot boundary, was estimated at 6/1000 km2 (Nagy and Branigan 1998). In the Lac de Gras area (Central Arctic), spanning the North Slave/Kitikmeot boundary, the bear density was estimated at 3.5/1000 km2 (Penner and Associates 1998; P. McLoughlin, pers. commun.). I assumed a typical density of 4/1000 km2 and applied it to an arbitrarily-defined area of 200 000 km2 in the northwestern corner of mainland Nunavut. This value is considered a reasonable guess for grizzly bear density across much of the Kitikmeot Region (B. Patterson, pers. commun.). The result was an estimate of 800 bears.

Grizzly bear densities in eastern mainland Nunavut are believed to be much lower, although no estimates exist (M. Campbell, pers. commun.; R. Mulders, pers. commun.). Consequently, I estimated a density of 1 bear/1 000 km2 for an area of 200 000 km2 extending west from the Hudson Bay coast, south from the Arctic Ocean coast, and north from the Manitoba border. This yielded an estimate of 200 bears, for a Nunavut total of 1000 bears. Accounting for uncertainty in density and extent of distribution, an estimated population range of 800-2000 bears is reasonable. Given the crude nature of these estimates, no assessment of population trend is possible. Local managers are aware of no major changes in grizzly populations in the Kitikmeot and Kivalliq regions over the past decade (B. Patterson, M. Campbell, pers. commun.).

Grizzly bears probably occupy most of mainland Nunavut (Figure 3). This distribution has likely not changed in historic times (Schwartz et al. in press).

Because of changes in jurisdictional boundaries, mortalities in Northwest Territories and Nunavut are considered jointly (Table 11). Hunter kills, DLP kills, and total mortalities fluctuated over the reporting period.

6.7 Canada

Overall population size and distribution of grizzly bears in Canada are not known to have changed since 1991. The total extent of occurrence may approximate 3 469 000 km2 as reported by Banci (1991) and McLellan and Banci (1999), although the current area of occupancy is probably closer to 2 574 000 km2

Humans kill a reported mean of 504 grizzly bears in Canada each year (Table 12). About 84% of these mortalities are by legal hunters (including First Nations). Defence of Life or Property (DLP) kills account for another 13%. Based on the estimates of total Canadian population size (Table 6), known man-caused mortality accounts for an average of about 2.0 to 2.4% of the grizzly bear population each year. This mortality rate is not distributed evenly across the jurisdictions.


Figure 13. Current (diagonally hatched) and historic (ca. 1800) distribution of grizzly bears in North America.

Figure 13. Current (diagonally hatched) and historic (ca. 1800) distribution of grizzly bears in North America.

Adapted from Servheen (1990).

 


Figure 14. Human population density in Canada by decade, 1861 to 2000.

Figure 14. Human population density in Canada by decade, 1861 to 2000.

 


Figure 15. Total human population of Alberta, British Columbia, Yukon, and Northwest Territories (including Nunavut), 1971 to 2000.

Figure 15. Total human population of Alberta, British Columbia, Yukon, and Northwest Territories (including Nunavut), 1971 to 2000.

Data from Statistics Canada.

6.8 Population size and trend--summary

The total grizzly bear population in Canada is estimated to be a minimum of 27 421, with a range of 26 916+ to 29 150+. Of these, 6 890+ to 17 199+ are of reproductive age. Grizzly bears currently occupy several discontinuous areas and therefore comprise several subpopulations. Eight population isolates have been identified along the southern fringe of grizzly bear distribution in BC, with a total population of <250 bears (T. Hamilton and B. McLellan, pers. commun.). For 6 of these units, population estimates are <30 bears each. For each of the remaining 2 units, estimates are 60-70 bears. The remainder of the Canadian grizzly population occupies some 2 574 000 km2 that is essentially continuous. Grizzly bears have been extirpated from the prairie ecozone.

Canadian grizzly populations have been greatly reduced from historic levels, but have remained essentially consistent since 1990. Even the small and isolated populations in southern BC are believed to be stable.

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