THE STATE OF THE POLAR BEAR REPORT 2023 The Global Warming Policy Foundation Briefing 67 Susan Crockford The State of the Polar Bear Report 2023 Susan Crockford Briefing 67, The Global Warming Policy Foundation © Copyright 2024, The Global Warming Policy Foundation iii Contents About the author iii Foreword v Executive summary v 1. Introduction 1 2. Conservation status 1 3. Population trends 5 4. Habitat and primary productivity 6 5. Human/bear interactions 11 6. Discussion 14 Bibliography 16 Notes 24 About the Global Warming Policy Foundation 26 About the author Dr Susan Crockford is an evolutionary biologist and has been working for more than 40 years in archaeozoology, paleozoology and forensic zoology.1 She is a former adjunct professor at the University of Victoria, British Columbia and works full time for a private consulting company she co-owns (Pacific Identifications Inc). She is the author of Eaten: A Novel (a science-based polar bear attack thriller), Polar Bear Facts and Myths (for ages seven and up, also available in French, German, Dutch, Portuguese, and Norwegian), Polar Bears Have Big Feet (for preschoolers), and several fully referenced books including, Polar Bear Evolution: A Model for the Origin of Species, Sir David Attenborough and the Walrus Deception, The Polar Bear Catastrophe That Never Happened, and Polar Bears: Outstanding Survivors of Climate Change,2 as well as a scientific paper on polar bear conservation status and a peer-reviewed paper on the distribution of ancient polar bear remains.3 She has authored several earlier briefing papers, reports, and videos for GWPF, as well as opinion pieces for major news outlets, on polar bear and walrus ecology and conservation.4 Susan Crockford blogs at www.polarbearscience.com. v Foreword This report is intended to provide a brief update on the habitat and conservation status of polar bears, with commentary regarding inconsistencies and sources of bias found in recent literature that won’t be found elsewhere. It is a summary of the most recent information on polar bears, relative to historical records, based on a review of 2023 scientific literature and media reports, and, in places, reiterates or updates information provided in previous papers. This publication is intended for a wide audience, including scientists, teachers, students, decision-makers, and members of the general public interested in polar bears and the Arctic sea ice environment. Executive summary 2023 marked 50 years of international cooperation to protect polar bears across the Arctic. Those efforts should be hailed as a conservation success story: from late-1960s population estimate by the US Fish and Wildlife Service of about 12,000 individuals, numbers have almost tripled, to just over 32,000 in 2023 (with a wide range of potential error for both estimates). • There were no reports from the Arctic in 2023 indicating polar bears were being harmed due to lack of suitable habitat, in part because Arctic sea ice in summer has not declined since 2007. • Contrary to expectations, a study in Svalbard found a decrease in polar bears killed in defense of life or property over the last 40 years, despite profound declines in sea ice over the last two decades. • A survey of Southern Hudson Bay polar bears in 2021 showed an astonishing 30% increase over five years, which adds another 223 bears to the global total. • A concurrent survey of Western Hudson Bay polar bears in 2021 showed that numbers had not declined since 2011, which also means they have not declined since 2004. Movement of polar bears across the boundaries with neighbouring subpopulations may account for the appearance of a decline, when none actually occurred. • The IUCN Polar Bear Specialist Group has ignored a 2016 recommendation that the boundaries of three Hudson Bay subpopulations (Western HB, Southern HB, and Foxe Basin) be adjusted to account for genetic distinctiveness of bears inhabiting the Hudson Bay region. A similar boundary issue in the western Arctic between the Chukchi Sea, and the Southern and Northern Beaufort subpopulations, based on known movements of bears between regions, has been acknowledged since 2014 but has not yet been resolved. • The US Fish and Wildlife Service and the IUCN Polar Bear Specialist Group, in their 2023 reports, failed to officially acknowledge the newfound South-East Greenland bears as the 20th subpopulation, despite undisputed evidence that this is a genetically distinct and geographically isolated group. Numbers are estimated at 234 individuals. 1 1. Introduction Fifty years ago, on 15 November 1973, the five Arctic nations of Canada, Russia, the USA, Norway and Greenland signed an international treaty to protect polar bears against the rampant overhunting that had taken place in the first half of the 20th century, and which had decimated many subpopulations. The treaty was effective, and by the late 1990s, polar bear populations that could be studied had at least doubled, making it a huge conservation success story. However, in 2009, the wording of the treaty was amended to protect the bears against on-going and future loss of sea ice habitat , which was assumed to be caused by human-generated greenhouse gas emissions. This was in line with similar declarations by the International Union for the Conservation of Nature (IUCN) and the US Endangered Species Act (USESA). These pessimistic conservation assessments, based on computer-modelled future declines rather than observed conditions, have been upheld ever since, even as the predicted relationship between polar bear survival and sea-ice loss has failed to emerge in the observational data.5 The current population of polar bears is large, and their historical range has not diminished due to habitat loss since 1979. Indeed, previously inhabited areas have been recolonised as numbers have recovered: recent data suggest that territory in Davis Strait used before 1970 during the summer ice-free period – by all ages and by pregnant females for maternity denning – is now being used once again.6. 2. Conservation status The IUCN, in their 2015 Red List assessment, provided by the Polar Bear Specialist Group (PBSG), again listed polar bears as ‘vulnerable’ to extinction, just as it did in 2006. Similarly, in 2023 the US Fish and Wildlife Service (USFWS) upheld its 2008 conclusion that polar bears were ‘threatened’ with extinction. In both instances, conservation status assessments have been based on computer-modelled predictions of future sea-ice conditions and assumed resultant population declines rather than current conditions.7 In Canada, the 2018 COSEWIC report assigned a status of ‘special concern’ to the species. This assessment had not changed by 2023.8 3. Population size at 2023 Global The latest official estimate for the global population, from 17 October 2023, is the PBSG estimate of 26,000 (range 22,000–31,000), arrived at in 2015 and unadjusted since then. In their 2023 assessment, the PBSG has failed to increase this estimate, even to account for undisputed, statistically-significant increases in two subpopulations and the addition of a newly-discovered subpopulation, which should reasonably boost their very conservative mid-point estimate to about 26,600: Kane Basin is up by 133, Southern Hudson Bay is up by 223, and newly-discovered SE Greenland adds another 234.9 2 However, survey results postdating preparation of the 2015 assessment, including those made public after July 2021 (for Davis Strait, Chukchi Sea, SE Greenland, Western Hudson Bay, and Southern Hudson Bay), plausibly brought the mid-point total to just over 32,000 (Figure 1).10 A plan to survey all Russian polar bear subpopulations between 2021 and 2023 seems to have been put on hold. In addition, an abundance estimate for the Viscount Melville subpopulation in the western Canadian Arctic has still not been released, even though a three-year survey completed in 2014 has produced other published data.11 Surveys of Lancaster Sound and East Greenland were completed in spring 2023, and these results, when released, may put the global population mid-point estimate well above 32,000.12 While there is a wide margin of potential error attached to this number, it is nowhere near the figure of 7,493 (6,660–8,325), implicit in the prediction that two thirds of the global population of polar bears would be gone by now, given the sea ice conditions prevailing since 2007.13 Note that the 2023 USFWS Status Report did not include the Kara Sea estimate of 3,200 bears, the Laptev Sea estimate of 1,000 bears, or the East Greenland estimate of 2,000 bears, figures that were used for the 2015 IUCN assessment. It also used the lowest of three available 2016 estimates for the Chukchi Sea, as discussed in the State of the Polar Bear Report 2021. 14 Although the USFWS report was published in August 2023, it also did not include results of the 2021 assessments of the Western and Southern Hudson Bay subpopulations that were published in November 2022, or the newly-discovered subpopulation of South East Greenland reported in June 2022.15. Figure1: Estimates of the global polar bear population, 1960 to date. 60 40 20 0 1960 000s 1980 2000 2020 3 Subpopulation survey results published in 2022 For detailed discussions of the changing status and abundance issues over time for all 19 subpopulations, see the State of the Polar Bear Report 2018. 16 Western Hudson Bay (WH) An aerial survey conducted in September 2021 generated a new subpopulation estimate of 618 (range 385–852), an apparent decline of 27% since the 2016 estimate of 842 (range 562–1121) and about a 40% decline from a 2011 estimate of 949 (range 618– 1280) that used similar survey methods. However, the WH 2021 report authors stated categorically that this apparent decline since 2011 was not statistically significant, in part due to evidence that some bears moved into neighbouring subpopulations combined with the large margins of error. While it seems inconceivable that a decline of 40% over 10 years could be statistically insignificant, recall that a similar conclusion was reached in 2015 regarding the 42% increase in abundance of Svalbard bears. Since the estimate calculated in 2004 was 935 (range 794–1076), it seems the abundance of WH polar bears has not changed since 2004.17 Note that a more comprehensive survey was conducted in 2011, generating an estimate of 1030 (range 754–1406). This became the official WH estimate used by the PBSG.18 Given the conclusions of the 2021 survey that the 2016 and 2021 estimates were not statistically different from the 2011 estimate, it appears that the 2021 comprehensive estimate of 1030 may still be the most valid figure for WH. The 2021 WH survey authors also made it clear that the most recent population estimate was not associated with poor ice conditions, since sea-ice levels had been as good as the 1980s in four out of the five years between 2017 and 2021. Confoundingly, they could not explain why adult females and subadults were underrepresented in the population. No evidence was provided for lack of prey, and although emigration to neighbouring Southern Hudson Bay was largely dismissed as an explanation, the possibility of a movement north into Foxe Basin was not explored. This is odd, since a 2016 genetic study suggested that the northern boundary for WH polar bears should be moved to the north of Southampton Island (a major denning area currently included in FB) and the SH boundary to the north of Akimiski Island in James Bay, adding the entire southern Hudson Bay coast in Ontario, as well as the Belcher Islands, to WH (currently included in SH), leaving only James Bay to represent SH.19 In 2023, the PBSG indicated the WH subpopulation was ‘likely decreasing’, based on the 2021 estimate of 618 bears. However, they did not include the caveat from the survey report that this apparent decline was not statistically significant, and also did not incorporate the conclusion of the 2022 Canadian Polar Bear Technical Committee (PBTC) that indigenous knowledge (IK) assessed this subpopulation as ‘increased’. Similarly, the 2023 assessment by the 4 USFWS listed WH as ‘likely decreased’, based on the 2016 survey only (2021 survey results were not included). It acknowledged that in 2022 IK considered this subpopulation to have ‘increased’.20 Southern Hudson Bay (SH) An aerial survey conducted in September 2021 generated a new subpopulation estimate of 1119 (range 860–1454), which represented a 30% increase over five years. The result was considered robust, and reflective of the true size of the population. However, another estimate, of 1003 (range 773–1302), was generated based on the same data. This was considered more comparable to the 2016 estimate of 780 (range 590–1029). While the authors did not explicitly address the issue of statistical significance, they concluded that a natural increase in numbers, via increased cub production and survival, must have taken place in conjunction with good sea ice conditions from 2017 to 2020, perhaps in addition to immigration from another unidentified subpopulation.21. In their 2023 assessment, the IUCN PBSG discussed the apparent increased abundance of SH bears, but did not unequivocally state that the subpopulation had increased, instead only implying that an increase may have been possible (‘years of relatively good ice conditions, combined with comparatively reduced harvest from 2016–2021 may have buffered the population against further decline or allowed for recovery’). They also did not include the 2022 assessment by the PBTC that IK considered the SH subpopulation was ‘stable/likely increased’ (i.e. stable in the James Bay portion, likely increased in southeastern Hudson Bay).22. The 2023 assessment by the USFWS listed SH as ‘likely decreased’, based only on 2016 survey results (2021 survey results were not included), but did acknowledge that in 2022, IK considered this subpopulation to be ‘stable/likely increased.’23. Southeast Greenland (SG) As part of a multiyear project on the status of SG polar bears that began in 2011, surveys were conducted during mid-March and mid-April of 2015–2017 for bears that lived below 64°N latitude. The results were compared with data from bears living in EG further north, which had been collected up to 2021. This southern region of Greenland had not previously been surveyed, or even visited by polar bear scientists, and there are no permanent human inhabitants. Few Inuit hunters even venture into the region.24 Based on capture-recapture data, a population estimate of 234 (range 111–462) was generated for SG. Weight (indicating body condition or fatness) of almost two dozen females captured in SG averaged 186 kg, which was similar to females in Svalbard in the western Barents Sea (185 kg) in the 1990–2000 period and in EG in recent years (186 kg). Most surprisingly, there was strong evidence that these SG polar bears are the most genetically distinct subpopulation in the Arctic, indicating a lack of interbreeding with bears in EG for at least 200 years.25. 5 Much emphasis was given by study authors Kirstin Laidre and colleagues to their interpretation that bears in these SG fjords frequently used glacier ice to hunt seals during the summer; in other locations bears only do so occasionally. Seals feed in such ‘glacier-front’ habitats in summer because primary productivity is high: melting glaciers in the fjords attract fish because their food – marine plankton – is plentiful. However, the only evidence provided of seal-hunting behaviour by polar bears in summer in SG is one photo, taken by an unidentified photographer, of a bear on glacier ice beside a seal kill taken in September 2016. As noted above, the SG polar bear surveys were conducted in March and April and therefore, frequent summer hunting of seals could not have been observed by the authors, but was simply assumed to have happened. In addition, although the authors imply that glacier-front habitat is rare, it is in fact rather common across the Arctic and widely used by polar bears year-round because the sea ice covering such fjords in late winter and spring (including those in SG) are used by ringed seals as a birthing platform. Moreover, newborn seals are the preferred prey of polar bears, making up roughly two thirds of their diet. Fjords with glacier ice are present all along both coasts of Greenland, in Svalbard, Novaya Zemlya and Franz Josef Land in Russia, and in Baffin and Ellesmere Islands in the Canadian Arctic.26 The authors concluded their report with a recommendation that SG be officially recognized by the IUCN PBSG as a polar bear subpopulation distinct from EG for management and conservation purposes. However, despite the fact that Dr Laidre is currently the co-chair of the PBSG, and that in March 2023 the government of Greenland declared SG a protected ‘new and separate management unit’, the PBSG declined to add it as a distinct subpopulation. The 2023 USFWS assessment cited the 2022 Laidre report and its abundance estimate for SG, but regarding a change in boundaries for EG, it stated only that, ‘ecoregion and subpopulation status will likely be re-evaluated by PBSG in 2023’.27 4. Population trends In Canada, where roughly two thirds of the world’s polar bear population live, a 2022 update from the PBTC for the first time included assessments based on Inuit IK for each of the 13 subpopulations for which Canada has sole or joint management responsibility. While the ‘scientific’ assessments for trends in abundance for these subpopulations are simply the widely varying ones provided by the PBSG in 2021, those based on IK were either ‘increased’ or ‘stable’.28 Later in 2022, the Government of Canada published updated global polar bear population trend maps based on 2021 PBSG ‘scientific’ data: no provision was made for the conflicting information from IK discussed above, calling into question whether IK assessments are actually given any weight in assessing current conditions.29 And while the 2023 USFWS assessment included the 2022 Canadian IK trend information in their status table, it gave 6 priority to 2021 PBSG scientific data.30 Figure 2 shows a more realistic representation of current polar bear population trends based on all available information (scientific survey results, IK, and studies on health and survival status published up to 31 December 2023, extrapolated to regions lacking recent survey data). This gives the following subpopulation classifications at 2023, including the new subpopulation of SE Greenland (SG): • seven ‘increasing’ or ‘likely increasing’ [KB, DS, MC, GB, CS, BS, SH]. • four ‘stable’ or ‘likely stable’ [BB, SB, WH, SG]. • nine ‘presumed stable or increasing’ [EG, LS, LP, KS, VM, NB, GB, FB, NW].