Species at Risk

The loss of biodiversity is a global concern. The international community is committing to halt the loss of biodiversity by 2020 and the United Nations declared the 2010-2020 period as the Decade of Biodiversity.

Species at risk indicators are one way to measure the status of biodiversity.

The vast majority of species in the NWT are secure and not at risk of extinction. Many NWT species that are categorized as “at risk” on national and international lists are at greater risk elsewhere in Canada or the world, but the NWT has responsibility for conserving large portions of their remaining populations.

Very few species in the NWT face threats that could drive them to extinction within 100 years or less.

The Species at Risk indicators in this report provide status and trend information on all species known to be at risk in the NWT. Some indicators also provide information on threats to some species at risk in the NWT. The information provided in these indicators is used for territorial, national and international reporting, and can be compared with indicators from other jurisdictions.

16.1. Trends in the Species At Risk Index.

This indicator tracks trends in future biodiversity loss in the NWT using the Species at Risk Index.

The Species at Risk Index (SARI) predicts the rate of future biodiversity loss based on the number and status of species at risk in an area. This allows us to track the likelihood of overall risk of species endangerment over the next 100 years. When the risk of overall species extinction worsens, the index goes up. On the other hand, when the species are less likely to become extinct, the index goes down.

The SARI calculation is based on the Red List Index3, which has been adopted to measure global progress towards stopping biodiversity loss4 . The SARI uses data from as far back as 1900, local knowledge, and formal species status assessments, enabling us to track the risk of extinction for the past 100 years.

The information used to calculate the current index is derived from species lists for the NWT28 and status assessments developed for Canada1,29. These assessments use quantitative criteria and project the risk of species extinction over the next 100 years or so. The index thus also provides a projection of extinction risk for the future, and can be compared with projections from other regions of the world.

NWT Focus

As in all northern regions, the NWT is home to fewer species than more temperate and tropical regions, but each species is well adapted to the harsh and variable northern environment. Short food webs and life at the limit of survival make northern ecosystems fragile. The effects of the loss of just one keystone species can have an irreversible impact on whole northern ecosystems. The SARI provides an overall look at how species in the NWT are doing. Both past problems and the current extinction risk of NWT species can be tracked using the SARI.

Current view: status and trend

The current SARI is about 1% for all species in the NWT. This means that, based on current threats, less than 1% of all tracked species in the NWT are at risk of becoming extinct.

The following graph shows the probability of species endangerment for each of the major groups of species in the NWT over the past 100 years. Changes in the SAR index for mammals illustrate how the SARI works. In the 1960s, the status of muskox improved as a result of protection measures. This is reflected in the decreased SARI measure at (a). In the 1970-80s, the status of grizzly bear, polar bear, wolverine, and caribou worsened, due largely to increasing human access and use of wildlife habitat, including increasing use of snowmobiles. This resulted in a upward trend in the SARI (b). In 2000, the status of bowhead whale improved after 60 years of hunting restrictions. This resulted in a decrease in the SARI seen at (c).

Graph: SARI calculated by ENR, based on status assessments following COSEWIC(1). Assessments back-casted prior to 1970 are based on literature and local knowledge of past species numbers and trends. Detailed information available from ENR. Circle notes for mammal SARI: a: status of muskox improved in the 1960s; b: status of grizzly bear, polar bear, wolverine, caribou worsen due mostly to increasing habitat use and access, including increasing use of snowmobiles; c: status of bowhead whale noted as improved after almost no hunting for the past 60 years. Number of species tracked is in parentheses.  

The risk of species endangerment for freshwater fishes, migratory birds, mammals, and amphibians has changed the most over the past 100 years. The NWT is home to only five species of amphibians and one reptile, all of which are at the extreme northern edge of their range. The assessment of two species as Special Concern has been enough to bring the overall risk of endangerment for this group up above any other group. Similarly, nine out of the 55 species of terrestrial and marine mammals in the NWT that are tracked are at some risk of extinction – and have been for 100 years or more – making the overall risk of endangerment for this group higher than others.

Looking forward

The risk of biodiversity loss for the NWT is extremely low and is expected to remain low in the near future. But recent species status assessments indicate that it may be slowly increasing. For example, arctic-nesting shorebirds and birds that are aerial insect feeders have rapidly declined in numbers during the past 20-30 years; red knots, common nighthawks, and olive-sided flycatchers are now at some risk of extinction and this will be reflected in the future index. The exact reasons for these declines are not known, but lessons from the past, for example the peregrine falcon, demonstrate that when threats are stopped or reduced, northern species can respond positively.

There are new challenges, including increasing habitat change, facing species in the NWT that may affect the probability of species survival. In some cases, we may have little control over the changes, such as climate change and land use decisions made in southern regions, that may threaten the survival of NWT species.

Looking around

The Red List Index has been calculated for migratory birds in large-scale regions of the world. The SARI for NWT birds can be compared to the Red List Index for birds in other regions. In 2004, the species survival probability for birds in the NWT was better than for birds in all other regions of the world. A similar index has not yet been calculated for other jurisdictions in Canada.

Find  more

• For more information on the COSEWIC list: www.cosewic.gc.ca
• For more information on the Red List: www.redlist.com
• Fore more information on the Convention of Biological Diversity and the 2010 Target: http://www.cbd.int/
• The Status of forest-associated species at risk is also a core indicator in the Forest Criteria and Indicators developed by the CCFM.

Other focal points

• See WILDLIFE for other indicators on populations of species at risk.
• See USE OF NATURAL RESOURCES for indicators on sustainable use of some species at risk.

Technical Notes

• Species At Risk Index (SARI)³ = (M-Tt)/M expressed as a percentage, where M (maximum threat score possible for any one tracked species) = W*N and T (current threat score for any one tracked species) = summation of all status weight for all tracked species at time t. W is highest possible status weight (= 4) and N is number of species tracked. Scores are Extinct = 4, Endangered = 3, Threatened = 2, Special Concern = 1, Not at Risk = 0. Status categories follow COSEWIC definition.
• The SARI is based on the Revised Red List Index³ and transformed 1-x.. . The range is from best = 0%, i.e., no species are at risk of becoming extinct,  to worst = 100%, i.e., all species are in danger of becoming extinct. Tracked species exclude species assessed as “Data Deficient” by COSEWIC¹ or ranked as “Undetermined” in the NWT²³. Percent of species that are tracked over the total number of native species in the NWT per group: 77% mammals; 100% amphibians-reptile; 81% birds; 56% freshwater fishes, 90% vascular plants²³.

NWT Species at Risk Index – Scores 2010

Scores based on COSEWIC¹ status

a - COSEWIC assesses the status of species using quantitative criteria similar to criteria used for the Red List (IUCN). Scores: Extinct = 4, Endangered = 3, Threatened = 2, Special Concern = 1, Not at Risk (not listed) = 0.
b - Average for two subspecies of Red Knot: rufa – 3; islandica – 1
c - Average for one species in two ecosystems: Peregrine Falcon – 1.
d - Status of all species in the Taiga Plains and Taiga Shield Ecozones are tracked as forest-associated species and reported to the CCFM Criteria and Indicators program.

Updated: 1 April 2011

16.2. Trends in NWT populations of species at risk in Canada

The Committee on the Status of Endangered Species in Canada (COSEWIC)1 assesses the status of species at risk in Canada. This indicator provides information on population trends for each NWT species that COSEWIC has designated as a species at risk in Canada.

Trend information is noted as either “increasing”, “decreasing” or “stable”. Uncertainties are noted.

Information on population trends is derived from COSEWIC reports1 with updates from ENR biologists and others as noted.

NWT Focus

For many species found in the NWT, threats to the survival of the species are more severe in areas outside the NWT than within the NWT. For some species such as grizzly, wolverine, wood bison, peregrine falcon, and boreal caribou, the people of the NWT are responsible for some of the only remaining healthy populations in North America or the world. Population status and trends for species at risk provide an overview of the current state of the most vulnerable components of northern ecosystems.

Current view: status and trend

There are 25 species or subspecies in the NWT that have been assessed as species at risk by COSEWIC. Of these, five species – forest and tundra sub-species of peregrine falcon, wood bison, whooping crane, and bowhead whales- have increasing populations in the NWT and five species - Peary caribou, northern mountain caribou, Dolphin-Union barren-ground caribou, red knot, and polar bear - have decreasing populations. Previously common species of insect-feeding birds, such as the common nighthawk, olive-sided flycatcher, and rusty blackbird, are becoming less common. These species have declining populations throughout North America, but the trend in NWT populations is uncertain. The recent trends in NWT populations of seven species at risk cannot be reliably determined.

Species at Risk	COSEWIC Status – Year of assessment	Percent of global distribution in Canada	Percent of Canadian distribution in NWT	Recent trend in NWT population(s)
Northern Arctic, Southern Arctic, and Northern Mountain Ecozones
Mammals
Peary Caribou	Endangered - 2004	100%	40%	Decreasing
Northern Mountain Caribou	Special Concern -2002	100%	20%	Decreasing for some herds
Dolphin-Union Barren-ground Caribou	Special Concern - 2004	100%	40%	Decreasing
Wolverine	Special Concern – 2003	20%	10-20%	Stable – Uncertain
Polar Bear	Special Concern - 2008	50%	10%	Stable to Decreasing
Grizzly	Special Concern – 2002	10-20%	20%	Stable – Uncertain
Birds
Red Knot (rufa)(1)	Endangered - 2007	100% (breeding distribution)	10%	Decreasing
Red Knot (islandica)(1)	Special Concern - 2007	40% (breeding distribution)	20%	Unknown
Peregrine Falcon (tundra-type)	Special Concern -2007	10%? (breeding distribution)	10%	Increasing
Eskimo Curlew	Endangered - 2009	- (uncertain distribution)	- (uncertain distribution)	N/A
Ivory Gull	Endangered - 2006	10% (breeding distribution)	0% (historical nesting site only)	N/A
Freshwater Fishes
Dolly Varden (northern form)	Special Concern - 2010	50%	50%		Decreasing - uncertain
Taiga Plains and Taiga Shield Ecozones
Mammals
Wood Bison	Threatened - 2000	100%	60%	Increasing for most herds
Boreal Caribou	Threatened - 2002	100%	10%	Stable – Uncertain in some regions
Birds
Whooping Crane	Endangered - 2010	Almost 100% (breeding distribution)	90%	Increasing
Rusty Blackbird	Special Concern – 2006	Almost 100% (breeding distribution)	10%	Stable – Uncertain
Olive-sided Flycatcher	Threatened – 2007	50% (breeding distribution)	10%	Unknown
Common Nighthawk	Threatened – 2007	40% (breeding distribution)	10%	Decreasing –Uncertain
Peregrine Falcon (forest type)	Special Concern –2007	10% (breeding distribution)	20%	Increasing
Short-eared Owl	Special Concern – 1994	10-30%   (breeding distribution)	10%	Unknown
Yellow Rail	Special Concern – 2009	10% (breeding distribution)	1%	Unknown
Canada Warbler	Threatened - 2008	80% (breeding distribution)	Less than 1%	Unknown
Horned Grebe	Special Concern - 2009	80% (breeding distribution)	10%	Stable - Uncertain
Freshwater Fishes
Shortjaw Cisco	Threatened – 2003	90%	Unknown	Unknown
Amphibians
Northern Leopard Frog	Special Concern – 2009	60%	2%	Decreasing - Uncertain
Western Toad	Special Concern – 2002	40%	Less than 1%	Unknown
Arctic Marine Ecozones
Mammals
Bowhead Whale	Special Concern - 2005	30%	30%	Increasing
Grey Whale	Special Concern - 2009	10%	Less than 1%	Increasing
Marine Fishes
Northern Wolffish	Threatened - 2001	20%	- (uncertain distribution)	Unknown

(1) Red Knot (rosellari): Threatened - 2007 may be present in the NWT, but this remains unconfirmed

Looking forward

Trends in populations of species at risk in the NWT are varied. Species with clearly increasing populations have either been the subject of intensive recovery efforts - peregrine falcon, wood bison, whooping crane - or the single threat to their survival has been halted for many decades - commercial hunting of bowhead whales. The reasons for continuing declines or uncertain population trends in other species at risk in the NWT differ for each species. Current threats to species at risk in the NWT include climate change, habitat use, prey declines, diseases, and over-hunting. Reducing the impacts of all these threats in the future will prove as challenging as in the past.

Find more

• For more information on species at risk in Canada: www.cosewic.gc.ca. Trends in populations of forest-associated species at risk are indicators in the Forest Criteria and Indicators developed by the CCFM. Forest-associated species at risk are those occurring the Taiga Shield, and Taiga Plains ecozones.
• See WILDLIFE for other indicators on populations of species at risk. See USE OF RENEWALBE RESOURCES for indicators on sustainable use of some species at risk.

Technical Notes

• Estimates of percent of distribution are based on printed material and were rounded to the nearest 10%, except for values less than 10 %. Increasing, Decreasing,
• Stable = population trends in the NWT, as measured or inferred, based written material;
• Uncertain = population trends uncertain or inferred based on expert opinion only;
• Unknown = population trend is not available and has not been measured or inferred based on any source.
• N/A = population trend cannot be measured or inferred due to lack of evidence of any breeding populations in the NWT.

Updated: 1 April 2011

16.3. Status of Peary Caribou in a changing climate

This indicator reports on the status of Peary caribou, a key species at risk, in NWT’s Arctic ecosystems. It also tracks changes in muskox populations, the only other large herbivore sharing the Peary caribou range. This indicator sheds light on the low carrying capacity of NWT’s most northern ecosystems, and on the effects of changing winter weather on the recovery of an endangered species.

Peary caribou and muskox population estimates are measured using multi-species aerial surveys performed at irregular intervals by ENR, GNWT.

NWT Focus

Peary caribou exist only in Canada; about 40% of the population is in the NWT. Peary caribou are considered endangered of becoming extinct in the next 100 years7. Hunting Peary caribou is permitted on Banks Island under a quota system. There has been a voluntary ban on hunting Peary caribou on NW Victoria Island since 1993, reviewed annually.

Muskoxen were intensively hunted until, by the 1930s, there were very few herds remaining in the barrenlands and some arctic islands. At one time considered to be on the brink of extinctions, muskoxen are no longer considered at risk of extirpation. Their numbers are increasing most rapidly on the mainland NWT and Nunavut17,11. Muskoxen are hunted in the NWT and there is a commercial harvest of an average of 342 muskoxen per year (range 0-1450, between 1998 and 2008) on Banks Island23,14.

Current view: status and trend

The High Arctic - Western Queen Elizabeth Islands - Prince Patrick, Melville, Bathurst and adjacent islands.

In 1961, a survey showed that the Western High Arctic Islands had about 5000 muskoxen and 24,000 Peary caribou21. In the winter of 1976, and then again in the winters of 1993-1995, large numbers of both species died off. Many carcasses of both Peary caribou and muskoxen were observed during these winters, and there was evidence of increased movements of animals between islands in search of a better range. There is evidence of at least some recovery between 1976 and 1993 on Bathurst Island. No surveys were conducted on Prince Patrick and Melville islands between 1988 and 1996, but signs of recovery followed by die-offs on these islands suggest that it is likely the same events affected all the High Arctic Islands. Evidence points to higher than normal snow cover and/or icing during winter as the cause of these large declines. To obtain food in winter, caribou and muskoxen must dig or paw down to the vegetation under the snow. This is easier in areas where wind has removed most of the snow, and in years of less snow. Rain in the fall can create ground-fast ice that restricts the availability of the animals to reach forage later in the winter. Years with the highest recorded snowfall (at Resolute Weather station) also showed die-offs: the winter of 1973/74, and the three consecutive winters of 1994/95, 1995/96, and 1996/97.

There is evidence that muskox and Peary caribou populations can recover if warm-snowy winters occur only rarely, but consecutive winters with late rain or high levels of snowfall are especially difficult for populations of the only two species of large herbivores adapted to live on the High Arctic islands. No surveys have been carried out on the High Arctic Islands since 1997, however two more consecutive winters with heavy snow were recorded in 2003/04 and 2004/0512. The impact of these winters on Peary caribou and muskox populations on the High Arctic islands is unknown.

Peary caribou and Muskox on Melville Island (NT), Prince Patrick Island (NT) and Bathurst Island (NU) Markers represent years with survey data. Error bars = 1 SE. Question marks represent expert opinion on population levels. Arrows and “d” mark years with evidence of die-off. Source: Muskox data: Fournier, B. and A. Gunn. 1997 Muskox numbers and distribution in the Northwest Territories, 1997.ENR File Report 121, 55 pp., Gunn, A. and Dragon, J. 2000 Peary Caribou and Muskox Abundance and Distribution on the Western Queen Elizabeth Islands, Northwest Territories and Nunavut June-July 1997 , ENR File Report 130, 87 pp. Peary caribou data: COSEWIC report 2004.

Banks Island

Surveys in 1972 showed that 3800 muskoxen and 12,098 Peary caribou were present on the island18. Unlike other islands, surveys have been conducted more regularly and in a more systematic fashion on Banks Island23. Surveys showed that by 1994, muskoxen had increased to about 64,000 and Peary caribou numbers had decreased to about 800. More recently, Muskox numbers have declined and the number of Peary caribou has increased slightly again7,20. Banks Island is relatively lush compared to the Queen Elizabeth islands, and its climate is milder. However, as on islands further north, unusually mild and wet winters, especially with freezing rain, have resulted in die-offs and lower calf production for muskox, and more notably for Peary Caribou in some years. The ecology of both species on Banks Island is still being studied. A combination of factors may explain the low recovery of caribou numbers after lowsurvival winters, including competition for food or feeding areas with muskox, increased predation pressure, and movement of caribou off the island. Caribou hunting is allowed under such a low quota that it may not be a significant pressure23. There is little weather data for Banks Island to track the effects of mild snowy winters and rain or snow events on large herbivores on the island.12 However, climate models and satellite data showed a severe rainfall event in October 2003, which resulted in a die-off of about half of the muskox population on the island.15

Peary caribou and Muskox on Banks Island (NT): Markers represent years with survey data. Error bars = 1 SE. Question marks represent expert opinion on population levels. Arrows and “d” mark years with evidence of die-off. Sources: Muskox data: Fournier, B. and A. Gunn. 1997 Muskox numbers and distribution in the Northwest Territories, 1997.ENR File Report 121, 55 pp., Gunn, A. and Dragon, J. 2000 Peary Caribou and Muskox Abundance and Distribution on the Western Queen Elizabeth Islands, Northwest Territories and Nunavut June-July 1997 , ENR File Report 130, 87 pp. Peary caribou data: COSEWIC report 2004. 2005 and 2010 updates: Nagy et. al. In press, Davison, Pongracz and Williams 2010 - Summary.

Looking forward

Warmer and often snowier winters have occurred more often in the High Arctic in the past two decades than before. If such warm winters become the norm, the prospects for a full recovery of populations of the endangered Peary caribou on NWT’s northern-most islands appear slim22 and the possibility of Peary caribou disappearing from many northern-most islands in the High Arctic is high. A slight increase in numbers of Peary caribou observed during the last survey on Banks Island may signal further recovery of that particular population in future years.

Muskox populations may abandon the High Arctic islands for better forage areas in a more southern range in the Southern Arctic. Muskox populations on the mainland in the NWT are variable26 . Despite population declines, especially in the northern-most part of their range, muskoxen populations have shown great capacity to recover quickly.

Looking around

Peary caribou and muskoxen also occur in Nunavut. Similar weather effects, interactions between the two species, and movements between islands have also been noted on Nunavut’s High Arctic Islands .

Find more

• To find more on Peary Caribou and Muskox ecology, go to www.enr.gov.nt.ca and follow the Wildlife links.
• To find more on species at risk such as Peary Caribou to go www.cosewic.gc.ca.

Other focal points

• See NATURAL CLIMATE FLUCTUATIONS and CLIMATE for indicators on weather events that affect Peary Caribou and Muskox in the High Arctic.
• See indicators on SUSTAINABLE USE of both species.

Technical Notes

• More information on trends in calf/cow ratio, survival rates, food and habitat selection of both species can be found in references below.

16.4. Status of peregrine falcons in a less contaminated world

This indicator tracks changes in an important raptor species, the peregrine falcon, a major predator on many species of birds and some small mammals. The indicator gives insights on how contaminants from other regions of the world affect a top predator species in NWT ecosystems.

Peregrine falcons are found on all continents of the world except Antarctica. Birds that nest in the NWT birds migrate to central and south America every winter. This raptor suffered a dramatic decline in numbers in the 1960-70s as bioaccumulation of pesticides ( DDT/DDE )in females caused their eggshells to thin, substantially increasing egg failure. A ban on DDT in North America and a reduction of its use around the world, in addition to recovery efforts such as the re-introduction of falcons in southern Canada and the US, have resulted in a marked increase in nesting adults.

As a top predator on birds, the peregrine falcon is an excellent indicator species for the overall chemical pollution present in all habitats used by the species and its prey. This indicator reports on the number of occupied nest sites and level of productivity measured during surveys performed regularly in two study areas in the NWT: the Mackenzie River study area in the Taiga Plains and the Daring Lake study area in the Southern Arctic.

In 2007, the peregrine falcon anatum/tundrius complex was re-assessed as a species of special concern by COSEWIC5. This is an improvement in status as the anatum type had been previously been assessed as threatened.

Information for this indicator is obtained from surveys performed every 5 years as part of North-American survey effort to measure the recovery of peregrine falcons across Canada and the US.

NWT Focus

Two eco-types of peregrine falcon nest in the NWT2. The tundrius type is found on the tundra in the Southern and Northern Arctic ecozones. The anatum type is found in forested ecosystems in the Taiga Plains27. Some peregrine falcon pairs also nest in the NWT’s Taiga Shield and Taiga Cordillera. There are 156 known peregrine falcon nesting sites on the tundra and at least 200 below the tree line (forested ecosystems). Not all sites are occupied in any given year and not all areas of the NWT have been surveyed for peregrine falcons so not all nesting sites are known.

Current view: status and trend

Mackenzie River – Taiga Plains

Very few historical nesting sites were occupied in the 1970s, when the systematic survey of peregrine falcon on the Mackenzie River was initiated. By the mid-1980s, this population was increasing rapidly and reached the highest number of occupied sites recorded in 2005 and 2010. Productivity, measured by the number of young per occupied sites in July, varies greatly from year to year. Annual productivity is influenced by weather and prey abundance, among other factors. Productivity, on average, has improved during the past 30 years as the effects of pesticides on falcon eggs diminished.

 Number of Peregrine Falcon sites observed, occupied by at least one bird, and productive with at least one chick along the Mackenzie River. Number of young observed per productive site and per occupied site. Source: Peregrine falcon nest sites are surveyed using standard protocols. Surveys are conducted using helicopters and boat on the Mackenzie River study area, and using helicopter and on foot . A boat survey is also conducted on the Mackenzie River study area.

Looking forward

NWT populations of peregrine falcons have recovered from the drastic declines observed in the 1960-70s. However, many pesticides, including DDT, are used in regions visited by peregrine falcons that next in the NWT6. In addition, contaminants such as brominated flame retardants10 and persistent organic pollutants9 are found in increasing amounts in the tissues of top arctic predators, including peregrine falcons, with still unknown effects on their reproductive success and survival. Peregrine falcons are a prized bird of prey for falconry and are harvested6 in small but increasing numbers in Canada, Mexico, and soon in the U.S. as well. Peregrine falcons are also susceptible to disturbance. NWT is home to some of the highest densities of nesting peregrine falcons in North America. Some of these high-density areas are being investigated for future protection under the NWT Protected Areas Strategy.

Looking around

Most populations of peregrine falcons nesting north of 60 have increased and seem to have recovered from the mid-century decline6. Recovery is slower and still under-way in southeastern Canada and eastern U.S.

Find out more

• For more information on COSEWIC go to www.cosewic.gc.ca
• Other surveys of peregrine falcons have been conducted in the NWT, including in Tuktut Nogait National Park and near the diamond mines SE of Daring Lake. Find more on these surveys in , but they are not reported here at this time.

Other focal points

• See SPECIES AT RISK for more information on status assessments and on COSEWIC.
• See CONTAMINANTS for indicators on the types and quantity of contaminants released to ecosystems in the NWT and elsewhere.

Technical Notes

• More information on the history of status assessment of peregrine falcon can be found the COSEWIC report in references below. Raw Data available under request from ENR.

Updated: 17 August 2011.

16.5 Status of Polar Bear and changing sea ice

This indicator tracks changes in the top predator in the Arctic, the Polar Bear.  The indicator gives information on Polar bear sub-population trends in the management areas found, at least partly, in the NWT: the Southern Beaufort Sea (SB), the Northern Beaufort Sea NB), and the Viscount Melville (VM).  The indicator links these trends to habitat changes in these areas.  Very few bears from the Arctic Basin management area may also move to the NWT, but they are not included in this indicator.

As a top predator, polar bear is an excellent indicator of the overall change in their arctic habitat, including multi-year sea ice used by some bears for denning, and in prey availability.

The indicator is compiled by ENR using information from COSEWIC⁸ and the IUCN/SSC Polar Bear Specialist Group. Data and analyses were obtained from studies by ENR, Environment Canada, the US Geological Survey. Sea ice trends are from the Canadian Ice Service⁵.   

NWT Focus

About 50% of Polar bear populations are found in Canada, of which about 10% are in the NWT.  In 2008, Polar bear was re-assessed as a species of special concern by COSEWIC⁶. 

Polar bears are an important resource to Inuvialuit people. Harvest management for bears that are the subpopulations most accessible to hunters is performed under the Inuvialuit-Inupiat Polar Bear Management Agreement in the Southern Beaufort and agreements between the Inuvialuit and Kitikmeot Hunter’s and Trappers Associations for the bears shared in the Northern Beaufort Sea and Viscount Melville Sound.  So in the Inuvialuit Settlement Area polar bear harvest is managed under strict quotas, where bear tags are assigned among communities for subsistence use, and tags not used can be re-assigned for sport hunting. Sport hunting is permitted only by dog sleds and accompanied by an Inuvialuit guide. 

Polar bear management is guided by the US/Canada MOU on Conservation and Management of Shared Polar Bear Populations. Trade in polar bear parts is guided by Appendix II of the Convention on the International Trade in Endangered Species (CITES).

Current view: status and trend

Analyses of population declines and hunting pressure are done for each management area (by sub-populations) separately but there is evidence that Polar bears in the NWT move long distances and there is interchange between the Northern and Southern Beaufort Sea management areas.⁸ 

Polar bears in the NWT feed almost exclusively on ringed seals, although bearded seals are also taken¹⁹.  Polar bears in the Beaufort Sea use multi-year ice to den, as well as land. Ice is important to all bears for traveling and hunting for ringed seals. Some bears in the Beaufort Sea never come to land and use ice all year round, moving north in summer and south again in winter.  In the US portion of the southern Beaufort Sea, the proportion of dens on the pack ice declined from 62% in 1985–1994 to 37% in 1998–2004¹³.  This change in denning behaviour may be related to changes and reductions in sea ice.  Increases in problem bear activity have been reported in recent years, including the Southern Beaufort Sea²⁴.

The Southern Beaufort Sea subpopulation appear to have experienced some decline in population in the recent past and the likelihood of decline in the near future is high (94%).  This predicted decline has been attributed to changes in sea ice in the western section of the population’s range along the shore of Alaska (see Big Picture – Sea Ice indicator).   

The polar bears in the Viscount Melville and Northern Beaufort Sea have been stable or increasing in numbers, and are less likely to decline in the near future based on population models, sea ice changes and moderate hunting pressure.  Polar bears in the Viscount Melville Sound may actually benefit, over the short-term, from the changing sea ice.  Less multi-year ice may result in increased abundance and accessibility to seals for that population.

Management Area	Den Habitat(a)	Sub-Population size(b)	Sub-Population trend - Observed(c)	Likelihood of future population decline(d)	Sea ice trend - Observed(e)	Hunting pressure index(f)
Viscount Melville (VM)	On land	99-331	Uncertain - Increasing?	Not likely	No change or increasing	69%
North Beaufort Sea (NB)	Multi-year ice, land	825-1135*	Stable - Increasing	Likely	No change	53%
South Beaufort Sea (SB)	Multi-year ice, land	1211-1841	Slightly Declining?	Very likely	No change or declining	66%

a Summary from Thiemann et al. 2008 (25)
b Data summary from COSEWIC 2008.(8) Year of last estimate: VM: 1992 (old, noted in italics), a survey is scheduled in VM for 2012; NB: 2006, SB: 2006.
c Analysis follows COSEWIC 2008 (8), based on evidence from population counts between 2006 and the 1980s, except for VM where all counts are from the 1990s, and from simulations to calculate the finite rate of increase, population viability analysis (PVA) including current hunting pressure, and conclusions reached by authors of the primary source listed for each subpopulation.  Trend for the NB is supported by TEK study (Paulatuk Oral History)(8).
d Results of PVA: proportion of simulations resulting in at least 30% future decline after 3 polar bear generations (36 years). VM = 7%; NB=42%; SB=94% chance of future declines.  
e Trend from Canadian Ice Service (5) See Focal Point 1 The Big Picture – A Changing Planet
f Index according to Thiemann et al. 2008(25), data summarized from COSEWIC 2008.  Index = Number of bears killed on average (2002-2007) divided by the total allowed quota for the sub-population(8) * 100. VM: 4.8 harvested /7 quota for NTand NU since 2004-2005; NB: 34.4 harvested /65 quota; SB: 53.4 harvested /81 quota).

Looking Around

• Some subpopulations shared by Canada and Greenland were until very recently subject to uncontrolled harvests. Of 13 subpopulations, 5 (Western Hudson Bay, Southern Beaufort Sea, Baffin Bay, Kane Basin, and Norwegian Bay), which represent approximately 28% of the total population of 15,500 polar bears shared by Canada and its immediate neighbours (Greenland and Alaska), have a greater than 50% risk of population decline by 30% or more over the next 36 years (3 bear generations). Those projected declines are partly attributable to climate change for Western Hudson Bay and Southern Beaufort Sea, but are mostly due to unsustainable harvest in Kane Basin and Baffin Bay.

Quote from COSEWIC 2008⁸

Technical notes

Abbreviations of management areas are Viscount Melville Sound (VM), Norwegian Bay (NW), Kane Basin (KB), Lancaster Sound (LS), Baffin Bay (BB), Davis Strait (DS) Southern Hudson Bay (SH), Western Hudson Bay (WH), Foxe Basin (FB), Gulf of Boothia (GB), M’Clintock Channel (MC), Southern Beaufort Sea (SB), and Northern Beaufort Sea (NB). Source: IUCN/SSC Polar Bear Specialist Group (2006).

Updated: 1 May 2011

Reference List

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Ref 3 - Butchart et al. 2009. Improvements to the Red List Index. PLoS ONE 2:e140 doi:10.1371/journal.pone.0000140

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Ref 5 - Canadian Ice Service.2009. Sea Ice  Overview, Environment Canada.

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Ref 12 - Environment Canada.  2004. Resolute CARS Historical Weather.  Available at http://www.climate.weatheroffice.ec.gc.ca/advanceSearch/searchHistoricDataStations_e.html .   EC, Canada.

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Ref 14 - Government of the Northwest Territories .2008. Summary of Harvest Data for Species Under quota in the Inuvialuit Settlement Region: July 2003 to June 2008.   Government of the Northwest Territories, DENR. Inuvik Region.

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Ref 24 - Schliebe S. L., T.J.Evans, S.Miller, C.J.Perham, J.Wilder. 2006. Summary of polar bear management in Alaska 2004/2005.  Report to the Canadian Polar Bear Technical Committee

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