Dr. Susan Crockford
Early last November, the sea ice around Svalbard was the lowest since 1967 and the female was pregnant simply not possible to the islands to the east of the archipelago and must instead make their nest and give birth in the ice or Franz Josef Land islands further to the east, as they had done before. However, the ice has returned this fall with a vengeance: even Hopen Island to the south of the region was surrounded by ice wells before the end of the month but will it attract a few females? Pregnant or not remains to be seen.
Results of monitoring the health of polar bears in Spring 2021 shows that the bears are doing well after last year’s low ice levels. Despite this evidence, a single bear take a picture to kill a reindeer in August 2020 is wrongly blamed about climate change. The story never seems to change.
Maternity density and sea ice
Polar bears are born in late December to early January and most females try to have a burrow ready for the event. Pregnant females who prefer to arrive east of Svalbard but are unable to reach these areas due to a lack of sea ice in the fall are thought to make their nests in the ice or in Franz Josef Land archipelago further east (Aars 2015; Aars et al. 2017; Andersen et al. 2012). This flexibility in the face of changing sea ice conditions is an obvious evolutionary survival mechanism that has provided species with the resilience needed to withstand natural sea ice variability. hundreds of thousands of years (both more rocks and much less ice compared to the present in 1980).
Polar bear vocalist Andrew Derocher spent several years studying Svalbard bears in late 1990s as summer sea ice conditions begin to change (Derocher 2005; Derocher et al. 2002, 2011). He totally accepts Ph.D. the supervisor’s baseless suggestion that only man-made global warming could account for the changes he witnessed (Crockford 2019). Despite the fact that recent studies have shown that the Svalbard bear is performing better now than it was in the 1980s (Lippold et al. 2019), he continues to relieve his ritual fears regardless whenever the Svalbard tape changes down (see below).
Bad conditions in Svalbard. Arrow shows Hopen Island. If the ice arrives in early November, over 20 females will give birth there. In recent years, sea ice has arrived too late for pregnant females to use the Island. 2020 is not looking good. https://t.co/CS7J50WRJE pic.twitter.com/rMdibACe0r– Andrew Derocher (@AEDerocher) November 9, 2020
The graph Derocher pulled from his 2011 paper on maternity coverage on Hopen Island compared to the amount of ice in the tweet above suggests that at least some women should use the island if sea ice reaches it. it before the end of November, like this year (see below). Hopen is the long skinny island on the southeastern edge of the ice (this island is actually easier to identify in the 2020 chart below):
However, monitoring data shows that no bear has been using the island since 2010 (below), although the fall ice cover was good late November 2019 and 2014, so it’s possible pregnant women have abandoned it now.
Sea ice in 2021 compared to previous years at the end of November
This year on November 29:
Compare with last year (2020) near this date:
And last year, in 2019:
And below, the Svalbard ice cover in late November from 2018 to 2012.
Bottom line: Despite the record fall in fall ice in 2020, outside this region there is the highest relative summer sea ice decline of all polar bear populations (Regehr et al. 2016), there is no sign sign of impending disaster in polar bear fabrication data spring 2021 or research done before about that (eg Lippold et al. 2019): no starving males, poor cubs, or large numbers of females without cubs. According to the models, last summer should have been the ‘booming point’ for this population. But the full ice winter and spring have grown as it always did and the bears still going strong, the same as in 2015 (Aars 2018; Aars et al. 2017).
Presenter
Aars, J. 2015. Research on polar bears at the Norwegian Polar Institute. Webinar (‘webinar”), January 14. pdf here.
Aars, J., Marques, TA, Lone, K., Anderson, M., Wiig, Ø., Fløystad, IMB, Hagen, SB and Buckland, ST 2017. Number and distribution of polar bears in the western Barents Sea. Polar research 36: 1. 1374125. doi:10.1080 / 17518369.2017.1374125
Andersen, M., Derocher, AE, Wiig, Ø. and Aars, J. 2012. Polar bears (Ursus maritimus) Maternity den distribution in Svalbard, Norway. Biological Pole 35: 499-508.
Crockford, SJ 2019. The polar bear disaster has never happened. Global Warming Policy Fund, London. Available in paperback and eBooks formats.
Derocher 2005. Population ecology of polar bears in Svalbard, Norway. Ecosystem population 47:267-275.
http://www.springerlink.com.ezproxy.library.uvic.ca/content/765147518rp35613/fulltext.pdf
Derocher, AE and Wiig, Ø. 2002 year. Postnatal length and body mass development of polar bears (Ursus maritimus) in Svalbard. London Zoological Journal 256: 343-349.
Derocher, AE, Andersen, M., Wiig, Ø., Aars, J. and Biuw, M. 2011. Sea ice and polar bear cave ecology at Hopen Island, Svalbard. Sea Ecological Progress Series 441: 273-279.
Lippold, A., Bourgeon, S., Aars, J., Andersen, M., Polder, A., Lyche, JL, Bytingsvik, J., Jenssen, BM, Derocher, AE, Welker, JM and Routti, H. 2019. Transient trends of persistent organic pollutants in Barents Sea polar bears (Ursus maritimus) associated with changes in feeding habits and body condition. Environmental Science and Technologyy 53 (2): 984-995.
Regehr, EV, Laidre, KL, Akçakaya, HR, Amstrup, SC, Atwood, TC, Lunn, NJ, Obbard, M., Stern, H., Thiemann, GW, & Wiig, Ø. 2016. Polar bear conservation status (Ursus maritimus) related to the expected sea ice decline. Biology letter Date 12: 20160556. http://rsbl.royalsocietypublishing.org/content/12/12/20160556
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