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Document selection of Chukchi Sea polar bears in 2020 – Watts Up With That?

Reposted from Dr. Susan Crockford’s Polar Endure Science.

Wrangel Island analysis workforce counted a file selection of Chukchi Sea polar bears in 2020

Posted on September 21, 2021 | Feedback Offon Wrangel Island analysis workforce counted a file selection of Chukchi Sea polar bears in 2020

Many Chukchi Sea polar bears spend the summer time on Wrangel Island and a survey there performed by means of Russian researchers in 2020 reportedly accumulated knowledge on a file 747 bears, neatly up from the 589 reportedly counted in 2017 by means of the similar workforce (picture beneath is from 2015).

Word the newest survey of the Chukchi Sea estimated about Three,000 bears inhabit the area (AC SWG 2018; Regehr et al. 2018), no less than 1,000 extra that the determine of two,000 utilized in contemporary IUCN tests and survival predictions (Amstrup et al. 2007; Regehr et al. 2016; Wiig et al. 2015). Wrangel Island is the principle terrestrial denning house within the Chukchi Sea (Garner et al. 1984; Rode et al. 2014) and a not too long ago printed learn about confirmed that the frame situation (i.e. fatness) and clutter dimension of Chukchi Sea polar bears has no longer been negatively suffering from low summer time sea ice (Rode et al. 2021).

In step with a brief venture document final week from polar undergo specialist Eric Regehr (previously at america Flora and fauna Provider, now College of Washington), filed on 14 September 2021 (‘Polar bears on Wrangel Island‘), Russian researchers on the Wrangel Island State Nature Reserve have been ready to proceed paintings that started in 2016 as a joint American/Russian venture. Covid-19 restrictions stored US researchers from taking part in 2020 and once more this 12 months.

There have been no main points supplied at the method of the learn about and no document at the paintings is but to be had. However relaxation confident that if any indicators of a inhabitants cave in or ravenous bears have been noticed, it could were headline information around the globe as a substitute of a ‘just right information’ tale at the Polar Bears World web site. To the contrary, the picture that accompanies Regehr’s article (beneath) seems to turn a feminine with 4 cubs-of-the-year, a unprecedented phenomenon additionally reported in 2017. Actually, it sounds just like the Chukchi Sea subpopulation continues to be ‘productive and heathly’ as Regehr advised the Day-to-day Mail they have been in 2017, regardless of markedly diminished summer time sea ice since 2007.

Polar undergo numbers on Wrangel Island since 2007

Even if strategies of counting and quantity of the island surveyed may not be similar between years (inconceivable to grasp at this level), here’s what the reported counts were 12 months to 12 months:

2020 747 bears (Regehr 2021)

2017 589 bears (Regehr, quoted within the Day-to-day Mail 2017)

2012 ~200-300 bears (Ovsyanikov and Menyushina 2015)

2013 ~200-300 bears (Ovsyanikov and Menyushina 2015)

2007 ~550-600 bears (Ovsyanikov 2010)

Sea ice stipulations

The selection of bears taking safe haven on Wrangel Island all over the summer time obviously varies 12 months to 12 months. This variability is also a serve as of native sea ice stipulations, which additionally range 12 months to 12 months, moderately than reflecting the entire numbers of bears within the subpopulation. Alternatively, opposite to predictions that loss of ice 12 months after 12 months will have to purpose inhabitants tension, counts of bears on Wrangel Island in ‘high-bear’ years have obviously larger since 2007 regardless of a corresponding decline in summer time sea ice.

This 12 months (at 19 September 2021), Wrangel Island continues to be virtually surrounded by means of ice, because it was once previous this month, which might imply that fewer bears have spent the summer time at the island. We gained’t know till subsequent 12 months, when this summer time’s survey effects are launched, if that has been the case or no longer.

In 2020 when the survey mentioned above discovered file numbers of polar bears, the pack ice was once neatly clear of Wrangel Island at the identical date (19 September), as proven beneath.

In a similar way in 2017, when 589 bears have been discovered on Wrangel, sea ice extent within the Chukchi Sea at mid-September (beneath) was once extra like 2020: a long way, a long way away.

Against this, in 2012 (at 13 September, see closeup beneath) there was once a patch of ice round Wrangel even if Chukchi Sea ice on the whole was once at an excessively low extent, with best about 200-300 bears counted at the island. That is what suggests counts for 2021 is also identical: almost certainly no longer as little as 2012 however less than 2020. In high-ice years like 2021, pregnant women might make up the majority of bears that spend the summer time on Wrangel. Time will inform if that’s the case.

References

AC SWG 2018. Chukchi-Alaska polar undergo inhabitants demographic parameter estimation. Eric Regehr, Medical Running Workforce (SWG. File of the Lawsuits of the 10th assembly of the Russian-American Fee on Polar Bears, 27-28 July 2018), pg. five. Revealed 30 July 2018. US Fish and Flora and fauna Provider. https://www.fws.gov/alaska/fisheries/mmm/polarbear/bilateral.htm pdf right here.

Amstrup, S.C., Marcot, B.G. & Douglas, D.C. 2007. Forecasting the rangewide standing of polar bears at decided on instances within the 21st century. US Geological Survey. Reston, VA. Pdf right here

Garner, G.W., Belikov, S.E., Stishov, M.S., Barnes Jr., V.G. and Arthur, S.M. 1984. Dispersal development of maternal polar bears from the denning focus on Wrangel Island. World Convention on Endure Analysis and Control (now URSUS) nine(1):401-410.

Regehr, E.V., Hostetter, N.J., Wilson, R.R., Rode, Okay.D., St. Martin, M., Communicate, S.J. 2018. Built-in inhabitants modeling supplies the primary empirical estimates of necessary charges and abundance for polar bears within the Chukchi Sea. Medical Reviews eight (1) DOI: 10.1038/s41598-018-34824-7  https://www.nature.com/articles/s41598-018-34824-7

Regehr, E.V., Laidre, Okay.L, Akçakaya, H.R., Amstrup, S.C., Atwood, T.C., Lunn, N.J., Obbard, M., Stern, H., Thiemann, G.W., & Wiig, Ø. 2016. Conservation standing of polar bears (Ursus maritimus) on the subject of projected sea-ice declines. Biology Letters 12: 20160556. http://rsbl.royalsocietypublishing.org/content material/12/12/20160556

Rode, Okay.D., Regehr, E.V., Douglas, D., Durner, G., Derocher, A.E., Thiemann, G.W., and Budge, S. 2014. Variation within the reaction of an Arctic most sensible predator experiencing habitat loss: feeding and reproductive ecology of 2 polar undergo populations. International Trade Biology 20:76-88. http://onlinelibrary.wiley.com/doi/10.1111/gcb.12339/summary

Rode, Okay.D., Regehr, E.V., Bromaghin, J.F., Wilson, R.R., Martin, M.S., Crawford, J.A. and Quakenbush, L.T. 2021. Seal frame situation and atmospheric stream patterns affect polar undergo frame situation, recruitment, and feeding ecology within the Chukchi Sea. International Trade Biology 27:2684-2701.

Ovsyanikov, N. 2010. Polar undergo analysis on Wrangel Island and within the central Arctic Basin. In, Lawsuits of the 15th assembly of the Polar Endure Experts Workforce IUCN/SSC, 29 June-Three July, 2009, edited by means of Obbard, M.E., Theimann, G.W., Peacock, E. and DeBryn, T.D., pp. 171-178. Gland, Switzerland and Cambridge UK, IUCN. pdf right here.

Ovsyanikov, N.G. and Menyushina, I. E. 2015. Demographic processes in Chukchi-Alaskan polar undergo inhabitants as noticed in Wrangel Island area. pg. 37-55, In: Marine Mammals of the Holarctic, Number of Medical Papers. Vol. 2. Moscow. pdf right here.

Wiig, Ø., Amstrup, S., Atwood, T., Laidre, Okay., Lunn, N., Obbard, M., et al. 2015. Ursus maritimus. The IUCN Pink Listing of Threatened Species 2015: e.T22823A14871490. To be had from http://www.iucnredlist.org/main points/22823/zero [accessed Nov. 28, 2015]. See the complement for inhabitants figures.

Reposted from Dr. Susan Crockford’s Polar Endure Science.

Wrangel Island analysis workforce counted a file selection of Chukchi Sea polar bears in 2020

Posted on September 21, 2021 | Feedback Offon Wrangel Island analysis workforce counted a file selection of Chukchi Sea polar bears in 2020

Many Chukchi Sea polar bears spend the summer time on Wrangel Island and a survey there performed by means of Russian researchers in 2020 reportedly accumulated knowledge on a file 747 bears, neatly up from the 589 reportedly counted in 2017 by means of the similar workforce (picture beneath is from 2015).

Word the newest survey of the Chukchi Sea estimated about Three,000 bears inhabit the area (AC SWG 2018; Regehr et al. 2018), no less than 1,000 extra that the determine of two,000 utilized in contemporary IUCN tests and survival predictions (Amstrup et al. 2007; Regehr et al. 2016; Wiig et al. 2015). Wrangel Island is the principle terrestrial denning house within the Chukchi Sea (Garner et al. 1984; Rode et al. 2014) and a not too long ago printed learn about confirmed that the frame situation (i.e. fatness) and clutter dimension of Chukchi Sea polar bears has no longer been negatively suffering from low summer time sea ice (Rode et al. 2021).

In step with a brief venture document final week from polar undergo specialist Eric Regehr (previously at america Flora and fauna Provider, now College of Washington), filed on 14 September 2021 (‘Polar bears on Wrangel Island‘), Russian researchers on the Wrangel Island State Nature Reserve have been ready to proceed paintings that started in 2016 as a joint American/Russian venture. Covid-19 restrictions stored US researchers from taking part in 2020 and once more this 12 months.

There have been no main points supplied at the method of the learn about and no document at the paintings is but to be had. However relaxation confident that if any indicators of a inhabitants cave in or ravenous bears have been noticed, it could were headline information around the globe as a substitute of a ‘just right information’ tale at the Polar Bears World web site. To the contrary, the picture that accompanies Regehr’s article (beneath) seems to turn a feminine with 4 cubs-of-the-year, a unprecedented phenomenon additionally reported in 2017. Actually, it sounds just like the Chukchi Sea subpopulation continues to be ‘productive and heathly’ as Regehr advised the Day-to-day Mail they have been in 2017, regardless of markedly diminished summer time sea ice since 2007.

Polar undergo numbers on Wrangel Island since 2007

Even if strategies of counting and quantity of the island surveyed may not be similar between years (inconceivable to grasp at this level), here’s what the reported counts were 12 months to 12 months:

2020 747 bears (Regehr 2021)

2017 589 bears (Regehr, quoted within the Day-to-day Mail 2017)

2012 ~200-300 bears (Ovsyanikov and Menyushina 2015)

2013 ~200-300 bears (Ovsyanikov and Menyushina 2015)

2007 ~550-600 bears (Ovsyanikov 2010)

Sea ice stipulations

The selection of bears taking safe haven on Wrangel Island all over the summer time obviously varies 12 months to 12 months. This variability is also a serve as of native sea ice stipulations, which additionally range 12 months to 12 months, moderately than reflecting the entire numbers of bears within the subpopulation. Alternatively, opposite to predictions that loss of ice 12 months after 12 months will have to purpose inhabitants tension, counts of bears on Wrangel Island in ‘high-bear’ years have obviously larger since 2007 regardless of a corresponding decline in summer time sea ice.

This 12 months (at 19 September 2021), Wrangel Island continues to be virtually surrounded by means of ice, because it was once previous this month, which might imply that fewer bears have spent the summer time at the island. We gained’t know till subsequent 12 months, when this summer time’s survey effects are launched, if that has been the case or no longer.

In 2020 when the survey mentioned above discovered file numbers of polar bears, the pack ice was once neatly clear of Wrangel Island at the identical date (19 September), as proven beneath.

In a similar way in 2017, when 589 bears have been discovered on Wrangel, sea ice extent within the Chukchi Sea at mid-September (beneath) was once extra like 2020: a long way, a long way away.

Against this, in 2012 (at 13 September, see closeup beneath) there was once a patch of ice round Wrangel even if Chukchi Sea ice on the whole was once at an excessively low extent, with best about 200-300 bears counted at the island. That is what suggests counts for 2021 is also identical: almost certainly no longer as little as 2012 however less than 2020. In high-ice years like 2021, pregnant women might make up the majority of bears that spend the summer time on Wrangel. Time will inform if that’s the case.

References

AC SWG 2018. Chukchi-Alaska polar undergo inhabitants demographic parameter estimation. Eric Regehr, Medical Running Workforce (SWG. File of the Lawsuits of the 10th assembly of the Russian-American Fee on Polar Bears, 27-28 July 2018), pg. five. Revealed 30 July 2018. US Fish and Flora and fauna Provider. https://www.fws.gov/alaska/fisheries/mmm/polarbear/bilateral.htm pdf right here.

Amstrup, S.C., Marcot, B.G. & Douglas, D.C. 2007. Forecasting the rangewide standing of polar bears at decided on instances within the 21st century. US Geological Survey. Reston, VA. Pdf right here

Garner, G.W., Belikov, S.E., Stishov, M.S., Barnes Jr., V.G. and Arthur, S.M. 1984. Dispersal development of maternal polar bears from the denning focus on Wrangel Island. World Convention on Endure Analysis and Control (now URSUS) nine(1):401-410.

Regehr, E.V., Hostetter, N.J., Wilson, R.R., Rode, Okay.D., St. Martin, M., Communicate, S.J. 2018. Built-in inhabitants modeling supplies the primary empirical estimates of necessary charges and abundance for polar bears within the Chukchi Sea. Medical Reviews eight (1) DOI: 10.1038/s41598-018-34824-7  https://www.nature.com/articles/s41598-018-34824-7

Regehr, E.V., Laidre, Okay.L, Akçakaya, H.R., Amstrup, S.C., Atwood, T.C., Lunn, N.J., Obbard, M., Stern, H., Thiemann, G.W., & Wiig, Ø. 2016. Conservation standing of polar bears (Ursus maritimus) on the subject of projected sea-ice declines. Biology Letters 12: 20160556. http://rsbl.royalsocietypublishing.org/content material/12/12/20160556

Rode, Okay.D., Regehr, E.V., Douglas, D., Durner, G., Derocher, A.E., Thiemann, G.W., and Budge, S. 2014. Variation within the reaction of an Arctic most sensible predator experiencing habitat loss: feeding and reproductive ecology of 2 polar undergo populations. International Trade Biology 20:76-88. http://onlinelibrary.wiley.com/doi/10.1111/gcb.12339/summary

Rode, Okay.D., Regehr, E.V., Bromaghin, J.F., Wilson, R.R., Martin, M.S., Crawford, J.A. and Quakenbush, L.T. 2021. Seal frame situation and atmospheric stream patterns affect polar undergo frame situation, recruitment, and feeding ecology within the Chukchi Sea. International Trade Biology 27:2684-2701.

Ovsyanikov, N. 2010. Polar undergo analysis on Wrangel Island and within the central Arctic Basin. In, Lawsuits of the 15th assembly of the Polar Endure Experts Workforce IUCN/SSC, 29 June-Three July, 2009, edited by means of Obbard, M.E., Theimann, G.W., Peacock, E. and DeBryn, T.D., pp. 171-178. Gland, Switzerland and Cambridge UK, IUCN. pdf right here.

Ovsyanikov, N.G. and Menyushina, I. E. 2015. Demographic processes in Chukchi-Alaskan polar undergo inhabitants as noticed in Wrangel Island area. pg. 37-55, In: Marine Mammals of the Holarctic, Number of Medical Papers. Vol. 2. Moscow. pdf right here.

Wiig, Ø., Amstrup, S., Atwood, T., Laidre, Okay., Lunn, N., Obbard, M., et al. 2015. Ursus maritimus. The IUCN Pink Listing of Threatened Species 2015: e.T22823A14871490. To be had from http://www.iucnredlist.org/main points/22823/zero [accessed Nov. 28, 2015]. See the complement for inhabitants figures.

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