Conditions Were Not Golden For Polar Bears In The 1980s Despite What Activist Expert Claims – Watts Up With That?
Reposted from Polar Bear Science
Does the next assertion stand as much as scrutiny – i.e. a reality test – of the scientific literature on polar bear ecology?
Within the Nineteen Eighties, “the males had been large, females had been reproducing usually and cubs had been surviving properly,” Amstrup stated. “The inhabitants seemed good.”
[Steven Amstrup, Anchorage Daily News (Borenstein and colleagues), 5 November 2021: ‘How warming affects Arctic sea ice and polar bears’]
In brief, it doesn’t.
In 2007, polar bear specialist Steven Amstrup was nearly single-handedly answerable for the failed survival mannequin that obtained polar bears categorized as ‘Threatened’ below the Endangered Species Act (ESA) within the US. He has admitted that he retired from the US Geological Survey and sought employment with activist group Polar Bears International (PBI) in 2012 as a result of he wished a much bigger bullhorn for his predictions of polar bear disaster than was permitted below his position as a authorities scientist (Crockford 2019). Sadly, he hasn’t been capable of refute my analysis exhibiting how and why he was mistaken in his prediction – and resolutely refuses to concede his mistake (Crockford 2017, Crockford 2019; Crockford and Geist 2018).
He and his group use naive and compliant media to present their propaganda as ‘news’. My impression concerning the position of PBI in selling a selected agenda is corroborated not solely by their mandate however in a revealing 2013 story in The Atlantic about PBI’s affect over media visiting Churchill, an excerpt of which is copied under [my bold]:
As a result of Polar Bears Worldwide operates in shut partnership with a tour firm in Churchill that owns nearly all of the permits and autos wanted to entry the animals on the tundra, the group has been capable of intercept a lot of the main media that come via city. They set up biologists and climatologists on the reporters’ buggies like scientific press brokers, making an attempt to verify an correct narrative comes throughout, and so they present B-roll footage of bears plunging into melting slush to assist newscasters illustrate the issue.
In previous years, although, PBI had gone out of its means to assist tv crews solely to really feel betrayed by the completed product: the reporters ignore local weather change altogether, or regurgitate the junk theories of local weather change deniers. Most tv crews are actually requested to signal memorandums of understanding, outlining sure tips, earlier than working with PBI. (As a rule, one PBI staffer instructed me, Robert [Buchanan, founder of PBI] regards all journalists as “pirates and thieves.”)“
John Mooallem, The Atlantic, 26 Might 2013: Martha Stewart and the Cannibal Polar Bears: A True Story
The primary week of November is designated ‘Polar Bear Week’ by PBI and so I’ve come to count on that there can be greater than the same old variety of media choices on the dire plight of the bears. This yr is not any exception. Nevertheless, on this occasion Amstrup has gone excessive in making claims that purport to assist his dire predictions with no reality checking or problem by the media.
Amstrup acknowledged categorically last week that polar bears “within the Nineteen Eighties” had been doing extraordinarily properly: in different phrases, all through the Arctic, for your entire decade – suggesting the 80s had been the great outdated days for this species. Nevertheless, I contend the scientific literature produced by his polar bear specialist colleagues doesn’t assist that declare.
The place polar bears weren’t doing properly within the Nineteen Eighties
- Western Hudson Bay, the subpopulation that continues to be used to foretell the way forward for polar bears worldwide
- Chukchi Sea
There have been solely 4 subpopulations which might be thought-about moderately well-studied within the Nineteen Eighties: solely Western Hudson Bay and the Southern Beaufort had had inhabitants surveys carried out by that point, whereas some work on physique situation and cub survival had additionally been carried out within the Barents and Chukchi Seas (Derocher 2005; Larsen 1985; Rode et al. 2014; Wiig et al. 1998). Restricted information on litter dimension and reproductive success had been obtainable for some years within the Nineteen Eighties for just a few different areas (Derocher 1999; Obbard et al. 2007; Ramsay and Stirling 1988).
Western Hudson Bay
As I focus on in The Polar Bear Catastrophe That Never Happened, poor physique situation, lowered reproductive charges and far lowered cub survival was a trademark of Western Hudson Bay polar bears in the 1980s and early Nineteen Nineties. That was earlier than declining sea ice was any type of concern. Nevertheless, it was additionally when polar bear numbers had been larger than they’d been in maybe a century or extra and too many bears relative to the meals provide was seen because the most probably clarification (Derocher 1991; Derocher and Stirling 1992, 1995; Ramsay and Stirling 1988; Stirling and Lunn 1997). Ian Stirling solved the issue of probably not with the ability to clarify this case to his personal satisfaction by embracing the concept of catastrophic man-made climate change and its assumed position in summer season sea ice loss.
Within the worst yr, polar bear researchers Ian Stirling and Malcolm Ramsay emphasised that the imply weight of pregnant females they encountered in 1983 was 37kgs lighter than in different years (Ramsay and Stirling 1988:615). These authors acknowledged:
“...bears of all age and intercourse courses in the summertime and autumn of 1983 appeared to us, on the time of seize, to be, on common, in poorer situation than at equal seasons within the years earlier and subsequent. Some qualitative behavioural observations corroborated this view. Throughout autumn, 1983, the city of Churchill recorded a bigger variety of bears feeding at its dump (Lunn & Stirling, 1985) than within the earlier three years and a better variety of human-bear incidents than in any yr of the earlier decade. Three cubs-of-the-year had been discovered deserted by their moms in autumn and close to hunger, one thing seen in no different yr.” [my bold]
In a single excessive instance, a feminine they encountered with three cubs-of-the yr in November 1983 weighed solely 99 kg (218 lb) however survived; by the next July she was pregnant once more and weighed a outstanding 410 kg (904 lb), see photograph under.
Total, survival of cubs, litter sizes and physique situation of pregnant polar bears in Western Hudson Bay declined in the course of the Nineteen Eighties over charges seen within the 60s and 70s, and then declined much more within the Nineteen Nineties (which was blamed on international warming). Amstup and his colleagues are completely satisfied to inform folks concerning the decline between the Nineteen Eighties and Nineteen Nineties whereas protecting silent on the earlier decline. Nevertheless, the proof of their scientific papers can’t be denied: in Western Hudson Bay, the Seventies (not the Nineteen Eighties) had been the most effective years for polar bears.
Chukchi Sea
Current research have proven that Chukchi Sea polar bears are thriving by all measures used to evaluate individual and population heath: physique situation has been higher than it was within the late Nineteen Eighties (when there was a shorter ice-free interval) and females are reproducing properly, with a lot of triplet litters reported which earlier than this time had been uncommon anyplace outdoors Western Hudson Bay within the Seventies (see photograph under of a litter of triplets about one yr outdated in 2010: hardly ever do all three members of a triplet litter survive to this age) (Rode and Regehr 2010; Rode et al. 2014, 2018).
As well as, Chukchi Sea ringed and bearded seals – the first prey of polar bears – had been additionally discovered to be doing significantly better within the 2000s (as much as 2013) than they had been within the Nineteen Eighties (Crawford et al. 2015), and preliminary information from on-going studies counsel this continues to be the case (Adam et al. 2019).
The documented statement that Chukchi Sea polar bears had been doing higher in the course of the 2000s than that they had been within the late Nineteen Eighties signifies that they might not have been doing notably properly within the Nineteen Eighties – definitely not in addition to Amstrup’s assertion suggests.
The Conundrum
Right here is the issue: there isn’t any doubt that summer season sea ice protection (extent) was excessive in the course of the Nineteen Eighties (relative to now, see graph under) and that polar bear inhabitants numbers by the late Nineteen Eighties showed signs of recovery after many years of over-hunting. Restrictions on looking imposed within the late Sixties and early Seventies meant extra younger males had been allowed to develop into very giant adults and the observe of killing females with cubs largely stopped. As a consequence, population sizes grew quickly.
The truth that the inhabitants dimension had elevated as much as and together with the Nineteen Eighties doesn’t imply the extent of summer season sea ice was a causative issue.
As I’ve pointed out previously, the thickness of sea ice and depth of snow over the ice in the course of the spring is thought to have a extra pronounced affect on polar bear well being and survival as a result of it impacts their capacity to catch as many seals as they require (Crockford 2017; 2019). What we don’t know is how a lot spring ice thickness and snow cowl has assorted over Hudson Bay and the Chukchi Sea – decade to decade – because the Seventies. Nevertheless, it’s doable that together with intensive summer season ice within the Nineteen Eighties, there was additionally thick spring ice and/or heavy snow over ice in each areas, which might account for the decrease weights of bears and poorer reproductive success.
It’s pertinent to know that early in his profession, a younger and impressionable Amstrup occurred to be concerned in capturing a bear from the Southern Beaufort in 1982 that weighed 1400 lb, proven under with its head in Amstrup’s lap. There isn’t any doubt this was a really giant bear that left a giant impression and is maybe the true origin of his declare that “males had been large”.
Additionally it is true that the utmost weight of grownup males captured in Foxe Basin within the Seventies and Nineteen Eighties had been just like Amstrup’s huge bear: about 1367 lb, with the common weight of males about 1200 lb (Derocher and Stirling 1998; Rode et al. 2014: Fig 5).
Nevertheless, 1400 lb is way from the document, which belongs to a male weighing 2,209 lb (1,002 kg) shot within the southern portion of the Chukchi Sea subpopulation vary in 1960.
As well as, Amstrup’s single 1400 lb bear was not a lot heavier than three grownup males bears captured in the course of the early years of the 2008-2013 survey of the Chukchi Sea (2008-2010), every of which weighed “over 1200 lbs” (Rode and Regehr 2010) and thus just like these within the 70s and 80s from Foxe Basin.
Additionally, there have been some images printed lately of some really huge fats bears, together with the one under from the Southern Beaufort (Kaktovik) the summer season of 2019 whose weight we have no idea (examine to the photograph from WH in 1984 above):
Conclusion
There’s sturdy proof from at the least two out of 4 well-studied populations that polar bears weren’t doing notably properly within the Nineteen Eighties: definitely not in addition to that they had been doing earlier than (Western Hudson Bay) or after (Chukchi Sea). It’s doubtless that different populations had been additionally not doing particularly properly in the course of the Nineteen Eighties, particularly Davis Strait bears which had been nonetheless recovering from focused over looking and a scarcity of prey as a result of over-hunting of harp seals (Peacock et al. 2013). We don’t know for certain as a result of the Davis Strait inhabitants was not assessed for the primary time till the Nineteen Nineties (Taylor and Lee; Taylor et al. 2006).
In different phrases, polar bear specialists didn’t know for certain precisely what physique dimension and cub survival circumstances had been like for polar bears in most of the unstudied or poorly-studied areas of the Arctic within the Nineteen Eighties – and for 2 out of the 4 for which they did have information the bears weren’t doing particularly properly. Due to this fact Amstrup’s statement last week that the Nineteen Eighties had been golden years for polar bears all through their vary was a falsehood he felt was mandatory to advertise his failed prediction that polar bears can be threatened with extinction by human-caused international warming at a while sooner or later.
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References
Adam, R., Bryan, A., Quakenbush, L., Crawford, J., and Biderman, L.2019. Bearded seal productiveness in Alaska utilizing harvest-based monitoring, 1975-2016. Poster presentation, Alaska Marine Science Symposium, 28 January-1 February.
Crawford, J.A., Quakenbush, L.T. and Citta, J.J. 2015. A comparability of ringed and bearded seal weight loss plan, situation and productiveness between historic (1975–1984) and up to date (2003–2012) intervals within the Alaskan Bering and Chukchi seas. Progress in Oceanography 136:133-150.
Crockford, S.J. 2017. Testing the speculation that routine sea ice protection of 3-5 mkm2 leads to a better than 30% decline in inhabitants dimension of polar bears (Ursus maritimus). PeerJ Preprints 19 January 2017. Doi: 10.7287/peerj.preprints.2737v1 Open entry. https://peerj.com/preprints/2737/
Crockford, S.J. 2019. The Polar Bear Disaster That By no means Occurred. International Warming Coverage Basis, London. Out there in paperback and ebook codecs.
Crockford, S.J. and Geist, V. 2018. Conservation Fiasco. Vary Journal, Winter 2017/2018, pg. 26-27. Pdf here.
Derocher, A.E. 1991. Inhabitants dynamics and ecology of polar bears in western Hudson Bay. Ph.D. Thesis, Univ. Alberta, Edmonton.
Derocher, A.E. 1999. Latitudinal variation in litter dimension of polar bears: ecology or methodology? Polar Biology 22:350-356.
Derocher, A.E. 2005. Inhabitants ecology of polar bears at Svalbard, Norway. Inhabitants Ecology 47:267-275. http://www.springerlink.com.ezproxy.library.uvic.ca/content/765147518rp35613/fulltext.pdf
Derocher, A.E. and Stirling, I. 1992. The inhabitants dynamics of polar bears in western Hudson Bay. pg. 1150-1159 in D. R. McCullough and R. H. Barrett, eds. Wildlife 2001: Populations. Elsevier Sci. Publ., London, U.Okay.
Summary. Reproductive output of polar bears in western Hudson Bay declined via the 1980’s from larger ranges within the 1960’s and 1970’s. Age of first copy elevated barely and the speed of litter manufacturing declined from 0.45 to 0.35 litters/feminine/yr over the research, indicating that the reproductive interval had elevated. Recruitment of cubs to autumn decreased from 0.71 to 0.53 cubs/feminine/yr. Cub mortality elevated from the early to late 1980’s. Litter dimension didn’t present any important development or important annual variation as a result of a rise in lack of the entire litter. Imply physique weights of females with cubs within the spring and autumn declined considerably. Weights of cubs within the spring didn’t decline, though weights of each feminine and male cubs declined over the research. The inhabitants is roughly 60% feminine, presumably because of the sex-biased harvest. Though estimates of inhabitants dimension should not obtainable from the entire interval over which we’ve weight and reproductive information, the adjustments in copy, weight, and cub mortality are in step with the predictions of a densitydependent response to growing inhabitants dimension. [my bold]
Derocher, A.E. and Stirling, I. 1995. Temporal variation in copy and physique mass of polar bears in western Hudson Bay. Canadian Journal of Zoology 73:1657-1665. http://www.nrcresearchpress.com/doi/abs/10.1139/z95-197
Derocher, A.E. and Stirling, I. 1998. Geographic variation in progress of polar bears (Ursus maritimus). Journal of Zoology London 245: 65–72. https://www.cambridge.org/core/journals/journal-of-zoology/article/abs/geographic-variation-in-growth-of-polar-bears-ursus-maritimus/038F98EECC07331D0EE9F75926B12025
Larsen, T. 1985. Polar bear denning and cub manufacturing in Svalbard, Norway. Journal of Wildlife Administration 49:320-326. http://www.jstor.org/discover/10.2307/3801524?uid=3739400&uid=2&uid=3737720&uid=4&sid=21101182267021
Obbard, M.E., McDonald, T.L., Howe, E.J., Regehr, E.V. and Richardson, E.S. 2007. Polar bear inhabitants standing in southern Hudson Bay, Canada. Administrative Report, U.S. Division of the Inside- U.S. Geological Survey, Reston, VA.
Peacock, E., Taylor, M.Okay., Laake, J., and Stirling, I. 2013. Inhabitants ecology of polar bears in Davis Strait, Canada and Greenland. Journal of Wildlife Administration 77:463–476. http://onlinelibrary.wiley.com/doi/10.1002/jwmg.489/abstract?deniedAccessCustomisedMessage=&userIsAuthenticated=false
Ramsay, M.A. and Stirling, I. 1988. Reproductive biology and ecology of feminine polar bears (Ursus maritimus). Journal of Zoology London 214:601-624. http://onlinelibrary.wiley.com/doi/10.1111/j.1469-7998.1988.tb03762.x/abstract
Rode, Okay. and Regehr, E.V. 2010. Polar bear analysis within the Chukchi and Bering Seas: A synopsis of 2010 discipline work. Unpublished report to the US Fish and Wildlife Service, Division of the Inside, Anchorage. pdf here.
Rode, Okay.D., Regehr, E.V., Douglas, D., Durner, G., Derocher, A.E., Thiemann, G.W., and Budge, S. 2014. Variation within the response of an Arctic high predator experiencing habitat loss: feeding and reproductive ecology of two polar bear populations. International Change Biology 20(1):76-88. http://onlinelibrary.wiley.com/doi/10.1111/gcb.12339/abstract
Rode, Okay. D., R. R. Wilson, D. C. Douglas, V. Muhlenbruch, T.C. Atwood, E. V. Regehr, E.S. Richardson, N.W. Pilfold, A.E. Derocher, G.M Durner, I. Stirling, S.C. Amstrup, M. S. Martin, A.M. Pagano, and Okay. Simac. 2018. Spring fasting habits in a marine apex predator gives an index of ecosystem productiveness. International Change Biology http://onlinelibrary.wiley.com/doi/10.1111/gcb.13933/full
Stirling, I. and Lunn, N.J. 1997. Environmental fluctuations in arctic marine ecosystems as mirrored by variability in copy of polar bears and ringed seals. In Ecology of Arctic Environments, Woodin, S.J. and Marquiss, M. (eds), pg. 167-181. Blackwell Science, UK.
Taylor, M., and Lee, J. 1995. Distribution and abundance of Canadian polar bear populations: a administration perspective. Arctic 48:147-154. http://arctic.synergiesprairies.ca/arctic/index.php/arctic/article/view/1236/1261
Taylor, M.Okay., Lee, J., Laake, J. and McLoughlin, P.D. 2006. Estimating inhabitants dimension of polar bears in Foxe Basin, Nunavut, utilizing tetracycline biomarkers. Authorities of Nunavut, Division of Setting, Last Wildlife Report. Iqaluit.
Wiig, O. 1998. Survival and reproductive charges for polar bears at Svalbard. Ursus 10:25±32
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