Polar bear scientists in 1965 published a consensus statement on population size, with no caveats that these were ‘wild guesses’ or not to be taken seriously. They quoted some of the same authorities that I did when I suggested a plausible baseline figure. Andrew Derocher, Steven Amstrup and others who say there has never been population estimates for the 1960 or 1970s are not defending science, they are lying to protect their ‘polar bears are all gonna die because of climate change’ narrative. No other biologists do this, even those who insist the species they study are at risk from human-caused global warming. You should ask why.
From the proceedings of the first conference on polar bears held in Fairbanks, AK in 1965 (Anonymous 1966), archived here, is this statement about population size from page 11 (the poor quality is in the originals, scanned by Google Books):
In arriving at my plausible estimate of about 10,000 (range 5,000-15,000) in the late 1960s as a baseline figure for the depleted population (Crockford 2019), I used the above estimates (Scott et al. 1959; Uspensky 1961 [spelled ‘Uspenski’ in some documents]; Harington 1965) as well as several other published accounts that came out after that conference was held (Larsen 1972; Lentfer 1965; Jonkel 1969; Brooks 1965; Lønø 1970). Note that the estimate by Scott and colleagues and several others were made while rampant over-hunting was still on-going everywhere except Russia: international protection was not enacted until 1973.
It has only been since the polar bear became an icon for the global warming narrative – and therefore inconvenient to acknowledge that population numbers had declined to a worrying degree by the late 60s and early 70s – that polar bear specialists insist no one had any idea how many bears there were then. This senseless battle about the baseline figure is not a scientific argument, it’s a political one.
Anonymous 1966. Polar Bears: Proceedings of the First International Scientific Conference on the Polar Bear, Fairbanks, Alaska, 6-10 September 1965. US Dept. of Interior. 72 pg. https://books.google.ca/books/about/Proceedings_of_the_First_International_S.html?id=-FFUzgEACAAJ&redir_esc=y
Brooks, J.W. and Lentfer, J. W. 1965. The polar bear: a review of management and research activities in Alaska with recommendations for coordinated international studies. Unpublished report of the Alaska Department of Fish and Game, Juneau. Presented at the First International Meeting of Scientists on Polar Bear, University of Alaska, Sept. 6-11, 1965.
Durner, G.M., Laidre, K.L, and York, G.S. (eds). 2018. Polar Bears: Proceedings of the 18th Working Meeting of the IUCN/SSC Polar Bear Specialist Group, 7–11 June 2016, Anchorage, Alaska. Gland, Switzerland and Cambridge, UK: IUCN.
Harington, C.R. 1965. The life and status of the polar bear. Oryx 8: 169-176.
Jonkel, C. 1969. Polar bear research in Canada. Canadian Wildlife Service Progress Notes 13.
Larsen, T. 1972. Norwegian polar bear hunt, management and research.Bears: Their Biology and Management 2: 159-164.
Lentfer, J.W. 1970. Polar bear research and conservation in Alaska, 1968-1969. Pg. 43-66 (Appendix VI), in Anonymous (eds.) Polar Bears: Proceedings of the 2nd Working Meeting of the Polar Bear Specialists Group, IUCN/SSC, 2-4 February 1970, Morges, Switzerland. IUCN Publications New Series, Supplementary paper No. 29. Gland, Switzerland and Cambridge UK, IUCN.
Lønø, O. 1970. The polar bear (Ursus maritimus Phipps) in the Svalbard area. Norsk Polarinstitutt Skrifter 149.
Regehr, E.V., Laidre, K.L, Akçakaya, H.R., Amstrup, S.C., Atwood, T.C., Lunn, N.J., Obbard, M., Stern, H., Thiemann, G.W., & Wiig, Ø. 2016. Conservation status of polar bears (Ursus maritimus) in relation to projected sea-ice declines. Biology Letters 12: 20160556. http://rsbl.royalsocietypublishing.org/content/12/12/20160556 Supplementary data here.
Scott, R. F., Kenyon, K. W., Buckley, J. L., and Olsen, S. T., 1959. Status and management of the polar bear and Pacific walrus. Transactions of the Twenty-Fourth North American Wildlife Conference 24: 366–373.
Uspenski, S. M., 1961. Animal Population Estimates in the Soviet Arctic, Priroda No. 8: 33–41. (reprinted in 1962 as Polar Record 71(11): 195–196).