The SI for the Harvey et al. attack paper on Dr. Susan Crockford’s polar bear views

While the journal still has not released the Supplementary information (SI) file for the Harvey et al. paper, viewable here. I have a copy of the SI here that lists the blogs used (45 on each side of the issue) and the methodology. After some prodding on his blog and on Twitter, co-author Bart Verheggen released it.

I offer it here in full for analysis and commentary, without comment of my own. That will come later. A PDF of it is also available, see the bottom of this post – Anthony

Supplementary information (Harvey et al. 2017)

Blogs used for this study.

A total of 90 blogs discussing AGW, and both Arctic ice extent and polar bears were found on the internet using the Google search engine, although some were already known to the first author. The internal search engines of the found blogs and site-restricted Google searches were used to evaluate blog content and score their positions on six statements as described in the main manuscript. Citation of Susan Crockford was also recorded. Blogs were assigned ‘science-based’ and ‘denier’ categories on the basis of their positions taken relative to those drawn by the IPCC on global warming (e.g. whether it is warming or not and the anthropogenic contribution). The assignment was confirmed by creating a distance matrix from the scores using absolute distance (Manhattan distance) and performing a hierarchical cluster analysis on the result (Ward.D2 method from R 3.3.3, R Core Team, 2017). Both methods yielded two large clusters with identical content. Some blogs expressed positive responses to multiple questions (e.g. Arctic ice is declining but it is due to natural forcings) therefore the total number of hits for a statement can be larger than the total number of blogs in a category. Blog entries until June 20, 2017 were used.

AGW supporting science-based blogs used for Figures 1 and 2.


A Walk On The Natural Side ( Advocacy for Animals ( Carbonbrief (

Churchill Polar Bears (

Climate Change: The Next Generation ( Climate Feedback (

Climate Plus (

Climate Science Watch ( Cool Green Science (

David Suzuki Foundation ( Defenders of Wildlife (

Discovery Kids ( Deep Climate (

Dot Earth ( EcoInternet (

Encounters Alaska ( Frontiersnorth (

Gizmodo (

GO3 Project ( Greendustries Blog ( GreenFacts (

Grist (

Heat is Online ( National Wildlife Federation ( Phys Org (

Planet 3.0 (

PLoS Blogs (

Polar Bears International ( Scholar and Rogues ( ScienceDaily (

Scientific American Blog ( Skeptical Science:

The Corkboard Blog (

The Frog That Jumped Out ( TheGreenGrok (

The Way Things Break ( Thin Ice Blog (

Think Progress ( Tom Dispatch ( UMass Blog (https:// Wildscreen Arkive (

World Wildlife Fund Canada (

Yale Climate Connections ( Yale Environment 360 (

York Blog (

AGW denying blogs used for Figures 1 and 2.

Blog entries until February 3, 2017 were used (all accessed on 3 February, 2017 along with blog histories). Blogs marked with an asterisk refer to those primarily using the Polar Bear Science blog (of Dr. Susan Crockford) as their main supporting reference.

*American Thinker (

*Bishop Hill ( Bjorn Lomborg (

*Breitbart (

*Climate Change Dispatch (

*Climate Depot (

*C Fact (

*Climategate (

*Climate Lessons ( Climate Sanity (

*Climatism ( C02 coalition (

*Daily Caller (

*Fix This Nation (

*Friends of Science (

*Gateway Pundit (

*Global Climate Science Scam (

*Greenie Watch (


*Hockey Schtick (

*Ice Age Now (

*International Climate Science Coalition (

*Junkscience (

Jennifer Marohasy (

New Zealand Climate Science Coalition (

*No Frakking Consensus (

*Not a lot of people know that (

*Notrickszone (

*Polar Bear Science (

*Powerline (

*Principia Scientific (

*Quixotes Last Stand ( Real Science ( Resilient Earth (

Scottish Sceptic (

Skeptic’s Corner:


*Tall Bloke (

*The Daily Caller:

The Rational Optimist (

* The View From Here (

*Tom Nelson (

*Tom Remington (

*Watts Up With That (

World Climate Report (

Methods for the Principal component analysis (PCA, Figure 2)

A broad keyword search on the internet and the ISI Web of Science database yielded 90 blogs (described above) and 92 peer reviewed papers reporting on both Polar bears and arctic ice. Author’s positions in papers were scored in in same “position space” defined by binary answers to the six statements formulated in the main papers and citation of Dr. Susan Crockford as an expert. Missing values were replaced by zero after scaling and centering to minimize the influence of the replacement. The final data matrix contained the sources in the rows and the scores in the columns. The PCA was conducted using the prcomp routine from R

3.3.3 (R Core Team, 2017). Papers were classified as controversial when they evoked critical comments and discussion in the peer reviewed literature., blogs were colour coded using the results of a hierarchical cluster analysis (Ward.D2 method from R 3.3.3, R Core Team, 2017). Datapoint were slightly jittered to improve visibility of overlapping points.

R Core Team (2017). R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. URL

References used to generate the PCA.



Aars J, Andersen M, Brenière A, Blanc S. 2015. White-beaked dolphins trapped in the ice and eaten by polar bears. Polar Research 34: 26612.

Amstrup SC, Stirling I, Smith TS, Perham C, Thiemann GW. 2006. Recent observations of intraspecific predation and cannibalism among polar bears in the southern Beaufort Sea. Polar Biology 29: 997-1002.

Amstrup SC, Caswell H, DeWeaver E, Stirling I, Douglas DC, Marcot BG, Hunter CM. 2009. Rebuttal of “Polar bear population forecasts: a public-policy forecasting audit”. Interfaces 39: 353-369.

Amstrup SC, DeWeaver ET, Douglas DC, Marcot BG, Durner GM, Bitz CM, Bailey DA.

2010. Greenhouse gas mitigation can reduce sea-ice loss and increase polar bear persistence. Nature 468: 955-958.

Amstrup SC, Marcot BG, Douglas DC. 2008. A Bayesian network modeling approach to forecasting the 21st century worldwide status of polar bears. Pages 213-268 in DeWeaver ET, Bitz CM, Tremblayand LB, eds. Arctic Sea Ice Decline: Observations, Projections, Mechanisms, and Implications. Washington, D.C: American Geophysical Union.

Andersen M, Aars J. 2016. Barents Sea polar bears (Ursus maritimus): population biology and anthropogenic threats. Polar Research 35 (art. 26029).

Armstrong JS, Green KC, Soon W. 2008. Polar bear population forecasts: A public-policy forecasting audit. Interfaces 38: 382-405.

Atwood TC, Marcot BG, Douglas DC, Amstrup SC, Rode KD, Durner GM, Bromaghin JF. 2016. Forecasting the relative influence of environmental and anthropogenic stressors on polar bears. Ecosphere 7: e01370.

Bajzak C, Bernhardt W, Mosnier A, Hammill M, Stirling I. 2013. Habitat use by harbour seals (Phoca vitulina) in a seasonally ice-covered region, the western Hudson Bay. Polar Biology 36: 477-491.

Bromaghin JF, McDonald TL, Stirling I, Derocher AE, Richardson ES, Regehr EV, Douglas DC, Durner GM, Atwood T, Amstrup SC. 2015. Polar bear population dynamics in the southern Beaufort Sea during a period of sea ice decline. Ecological Applications 25:634- 651.

Castro de la Guardia L, Derocher AE, Myers PG, Terwisscha van Scheltinga AD, Lunn NJ. 2013. Future sea ice conditions in Western Hudson Bay and consequences for polar bears in the 21st century. Global Change Biology 19:2675-2687.

Chambellant M, Stirling I, Ferguson SH. 2013. Temporal variation in western Hudson Bay ringed seal Phoca hispida diet in relation to environment. Marine Ecology Progress Series 481: 269-287.

Cherry SG, Derocher AE, Thiemann GW, Lunn NJ. 2013. Migration phenology and seasonal fidelity of an Arctic marine predator in relation to sea ice dynamics. Journal of Animal Ecology 82:912-921.

Derocher AE. 2010. Climate change: The prospects for polar bears. Nature 468:905-906. Derocher AE, Aars J, Amstrup SC, Cutting A, Lunn NJ, Molnár PK, Obbard ME, Stirling I,

Thiemann GW, Vongraven D. 2013. Rapid ecosystem change and polar bear conservation. Conservation Letters 6: 368-375.

Derocher AE, Lunn NJ, Stirling I. 2004. Polar bears in a warming climate. Integrative and Comparative Biology 44: 163-176.

Derocher AE, Andersen M, Wiig Ø, Aars J, Hansen E, Biuw M. 2011. Sea ice and polar bear den ecology at Hopen Island, Svalbard. Marine Ecology Progress Series 441: 273-279.

Durner GM, Amstrup SC, Ambrosius KJ. 2006. Polar bear maternal den habitat in the Arctic National Wildlife Refuge, Alaska. Arctic 59: 31-36.

Durner GM, Douglas DC, Nielson RM, Amstrup SC, McDonald TL, Stirling I, Mauritzen M, Born EW, Wiig Ø, DeWeaver E. 2009. Predicting 21st-­‐century polar bear habitat distribution from global climate models. Ecological Monographs 79: 25-58.

Durner GM, Whiteman JP, Harlow HJ, Amstrup SC, Regehr EV, Ben-David M. 2011.

Consequences of long-distance swimming and travel over deep-water pack ice for a female polar bear during a year of extreme sea ice retreat. Polar Biology 34: 975-984.

Dyck MG, Kebreab E. 2009. Estimating the energetic contribution of polar bear (Ursus maritimus) summer diets to the total energy budget. Journal of Mammalogy 90: 585-593.

Dyck MG, Soon W, Baydack R, Legates D, Baliunas S, Ball T, Hancock L. 2007. Polar bears of western Hudson Bay and climate change: Are warming spring air temperatures the “ultimate” survival control factor? Ecological Complexity 4: 73-84.

Dyck MG, Soon W, Baydack RK, Legates DR, Baliunas S, Ball TF, Hancock LO. 2008. Reply to response to Dyck et al. (2007) on polar bears and climate change in western Hudson Bay by Stirling et al. (2008). Ecological Complexity 5: 289-302.

Fagre AC, Patyk KA, Nol P, Atwood T, Hueffer K, Duncan C. 2015. A review of infectious agents in polar bears (Ursus maritimus) and their long-term ecological relevance.

EcoHealth 12: 528-539.

Fischbach AS, Amstrup SC, Douglas DC. 2007. Landward and eastward shift of Alaskan polar bear denning associated with recent sea ice changes. Polar Biology 30: 1395-1405.

Galicia MP, Thiemann GW, Dyck MG, Ferguson SH, Higdon JW. 2016. Dietary habits of polar bears in Foxe Basin, Canada: possible evidence of a trophic regime shift mediated by a new top predator. Ecology and Evolution 6: 6005-6018.

Gormezano LJ, Rockwell RF. 2013. What to eat now? Shifts in polar bear diet during the ice-­‐free season in western Hudson Bay. Ecology and Evolution 3: 3509-3523.

Hamilton SG, Castro de la Guardia L, Derocher AE, Sahanatien V, Tremblay B, Huard D.

2014. Projected Polar Bear Sea Ice Habitat in the Canadian Arctic Archipelago. PloS one 9 (art. e113746).

Hobson KA, Stirling I, Andriashek DS. 2009. Isotopic homogeneity of breath CO2 from fasting and berry-eating polar bears: implications for tracing reliance on terrestrial foods in a changing Arctic. Canadian Journal of Zoology 87: 50-55.

Hoover C, Pitcher T, Christensen V. 2013. Effects of hunting, fishing and climate change on the Hudson Bay marine ecosystem: II. Ecosystem model future projections. Ecological Modelling 264: 143-156.

Hunter CM, Caswell H, Runge MC, Regehr EV, Amstrup SC, Stirling I. 2010. Climate change threatens polar bear populations: a stochastic demographic analysis. Ecology 91:2883-2897.

Iacozza J, Ferguson SH. 2014. Spatio-temporal variability of snow over sea ice in western Hudson Bay, with reference to ringed seal pup survival. Polar biology, 37: 817-832.

Iverson SA, Gilchrist HG, Smith PA, Gaston AJ, Forbes MR. 2014. Longer ice-free seasons increase the risk of nest depredation by polar bears for colonial breeding birds in the Canadian Arctic. Proceedings of the Royal Society of London B: Biological Sciences 281: 20133128.

Kirk CM, Amstrup S, Swor R, Holcomb D, O’Hara TM. 2010a. Morbillivirus and Toxoplasma exposure and association with hematological parameters for southern Beaufort Sea polar bears: potential response to infectious agents in a sentinel species. Ecohealth 7: 321-331.

Kirk CM, Amstrup S, Swor R, Holcomb D, O’Hara TM. 2010b. Hematology of Southern Beaufort Sea polar bears (2005–2007): biomarker for an arctic ecosystem health sentinel. EcoHealth 7: 307-320.

Kutschera VE et al. 2016. High genetic variability of vagrant polar bears illustrates importance of population connectivity in fragmented sea ice habitats. Animal Conservation, 19: 337-349.

Laidre KL, Born EW, Heagerty P, Wiig Ø, Stern H, Dietz R, Aars J, Andersen M. 2015.

Shifts in female polar bear (Ursus maritimus) habitat use in East Greenland. Polar Biology 38: 879–893.

Lunn NJ, Regher EV, Servanty S, Converse SJ, Richardson ES, Stirling I. 2014. Demography and population status of polar bears in western Hudson Bay. Environment Canada Research Report.

Lunn NJ, Servanty S, Regehr EV, Converse SJ, Richardson E, Stirling I. 2016. Demography of an apex predator at the edge of its range–impacts of changing sea ice on polar bears in Hudson Bay. Ecological Applications 26: 1302-1320.

Luque SP, Ferguson SH, Breed GA. 2014. Spatial behaviour of a keystone Arctic marine predator and implications of climate warming in Hudson Bay. Journal of Experimental Marine Biology and Ecology 461: 504-515.

Matejova M. 2015. Is Global Environmental Activism Saving the Polar Bear? Environment: Science and Policy for Sustainable Development, 57: 14-23.

McCall AG, Derocher AE, Lunn NJ. 2015. Home range distribution of polar bears in western Hudson Bay. Polar Biology 38: 343-355.

McCall AG, Pilfold NW, Derocher AE, Lunn NJ. 2016. Seasonal habitat selection by adult female polar bears in western Hudson Bay. Population Ecology 3: 407-419.

McKinney MA, Iverson SJ, Fisk AT, Sonne C, Rigét FF, Letcher RJ, Arts MT, Born EW, Rosing-Asvid A, Dietz, R. 2013. Global change effects on the long-­‐term feeding ecology and contaminant exposures of East Greenland polar bears. Global Change Biology, 19: 2360-2372.

McKinney MA, Atwood T, Dietz R, Sonne C, Iverson SJ, Peacock E. 2014. Validation of adipose lipid content as a body condition index for polar bears. Ecology and Evolution 4: 516-527.

Molnár PK, Derocher AE, Klanjscek T, Lewis MA. 2011. Predicting climate change impacts on polar bear litter size. Nature Communications 2: 186.

Molnár PK, Derocher AE, Thiemann GW, Lewis MA. 2010. Predicting survival, reproduction and abundance of polar bears under climate change. Biological Conservation 143: 1612- 1622.

Nuijten R, Hendriks A, Jenssen B, Schipper A. 2016. Circumpolar contaminant concentrations in polar bears (Ursus maritimus) and potential population-level effects. Environmental Research 151: 50-57.

Obbard ME, McDonald TL, Howe EJ, Regehr EV, Richardson ES. 2007. Trends in abundance and survival for polar bears from Southern Hudson Bay, Canada, 1984–2005. Administrative Report, USGS Alaska Science Center, Anchorage, AK.

Obbard ME, Stapleton S, Middel KR,Thibault I, Brodeur V, Jutras C. 2015. Estimating the abundance of the Southern Hudson Bay polar bear subpopulation with aerial surveys. Polar Biology 38: 1713-1725

O’Neill SJ, Osborn TJ, Hulme M, Lorenzoni I, Watkinson AR. 2008. Using expert knowledge to assess uncertainties in future polar bear populations under climate change. Journal of Applied Ecology 45: 1649-1659.

Owen MA, Swaisgood RR, Slocomb C, Amstrup SC, Durner GM, Simac K, Pessier AP.

2015. An experimental investigation of chemical communication in the polar bear. Journal of Zoology 295: 36-43.

Pagano AM, Durner GM, Amstrup SC, Simac KS, York GS. 2012. Long-distance swimming by polar bears (Ursus maritimus) of the southern Beaufort Sea during years of extensive open water. Canadian Journal of Zoology 90: 663-676.

Parsons ECM, Cornick LA. 2013. Politics, people and polar bears: A rebuttal of Clark et al. (2013). Marine Policy 42: 178-179.

Peacock E, Derocher A, Thiemann G, Stirling I. 2011. Conservation and management of Canada’s polar bears (Ursus maritimus) in a changing Arctic Canadian Journal of Zoology 89: 371-385.

Peacock E, Taylor MK, Laake J, Stirling I. 2013. Population ecology of polar bears in Davis Strait, Canada and Greenland. The Journal of Wildlife Management 77: 463-476.

Peacock E et al. 2015. Implications of the circumpolar genetic structure of polar bears for their conservation in a rapidly warming Arctic. PLoS One 10: e112021.

Pilfold NW, Derocher AE, Stirling I, Richardson E. 2015. Multi-­‐temporal factors influence predation for polar bears in a changing climate. Oikos 124: 1098-1107.

Regehr EV, Hunter CM, Caswell H, Amstrup SC, Stirling I. 2010. Survival and breeding of polar bears in the southern Beaufort Sea in relation to sea ice. Journal of Animal Ecology 79:117-127.

Regehr EV, Amstrup SC, Stirling I. 2006. Polar bear population status in the southern Beaufort Sea. USGS Report No. 2006-1337.

Regehr EV, Lunn NJ, Amstrup SC, Stirling I. 2007. Effects of earlier sea ice breakup on survival and population size of polar bears in western Hudson Bay. Journal of Wildlife Management 71: 2673-2683.

Regehr EV, Laidre KL, Akçakaya HR, Amstrup SC, Atwood TC, Lunn NJ, Obbard M, Stern H, Thiemann GW, Wiig Ø. 2016. Conservation status of polar bears (Ursus maritimus) in relation to projected sea-ice declines. Biology Letters 12: 20160556.

Rode KD, Amstrup SC, Regehr EV. 2010a. Reduced body size and cub recruitment in polar bears associated with sea ice decline. Ecological Applications 20: 768-782.

Rode KD, Reist JD, Peacock E, Stirling I. 2010b. Comments in response to “Estimating the energetic contribution of polar bear (Ursus maritimus) summer diets to the total energy budget” by Dyck and Kebreab (2009). Journal of Mammalogy 91: 1517-. 3.

Rode KD, Peacock E, Taylor M, Stirling I, Born EW, Laidre KL, Wiig Ø. 2012. A tale of two polar bear populations: ice habitat, harvest, and body condition. Population Ecology 54: 3- 18.

Rode KD, Regehr EV, Douglas DC, Durner G, Derocher AE, Thiemann GW, Budge SM.

2014. Variation in the response of an Arctic top predator experiencing habitat loss: feeding and reproductive ecology of two polar bear populations. Global Change Biology 20: 76-88.

Rode KD, Robbins CT, Nelson L, Amstrup SC. 2015. Can polar bears use terrestrial foods to offset lost ice-­‐based hunting opportunities? Frontiers in Ecology and the Environment 13: 138-145.

Rühland KM, Paterson AM, Keller W, Michelutti N, Smol JP. 2013. Global warming triggers the loss of a key Arctic refugium. Proceedings of the Royal Society of London B: Biological Sciences 280: 20131887.

Sahanatien V, Derocher AE. 2012. Monitoring sea ice habitat fragmentation for polar bear conservation. Animal Conservation 15: 397-406.

Sahanatien V, Peacock E, Derocher AE. 2015. Population substructure and space use of Foxe Basin polar bears. Ecology and Evolution, 5: 2851-2864.

Stapleton S, Atkinson S, Hedman D, Garshelis D. 2014. Revisiting Western Hudson Bay: using aerial surveys to update polar bear abundance in a sentinel population. Biological Conservation 170: 38-47.

Stern HL, Laidre KL. 2016. Sea-ice indicators of polar bear habitat. The Cryosphere 10: 2027. Stirling I, Derocher AE. 1993. Possible impacts of climatic warming on polar bears. Arctic

46: 240-245.

Stirling I, Parkinson CL. 2006. Possible effects of climate warming on selected populations of polar bears (Ursus maritimus) in the Canadian Arctic. Arctic 59: 261-275.

Stirling I, Lunn NJ, Iacozza J. 1999. Long-term trends in the population ecology of polar bears in western Hudson Bay in relation to climatic change. Arctic 52: 294-306.

Stirling I, Derocher AV. 2012. Effects of climate warming on polar bears: a review of the evidence. Global Change Biology 18: 2694-2706.

Stirling I, Derocher AE, Gough WA, Rode K. 2008. Response to Dyck et al. (2007) on polar bears and climate change in western Hudson Bay. Ecological Complexity 5: 193-201.

Stirling I, Richardson E, Thiemann GW, Derocher AE. 2008. Unusual predation attempts of polar bears on ringed seals in the southern Beaufort Sea: possible significance of changing spring ice conditions. Arctic 61: 14-22.

Stirling I, McDonald TL, Richardson ES, Regehr EV. 2007. Polar bear population status in the Northern Beaufort Sea. USGS Alaska Science Center, Anchorage, Administrative Report.

Stirling I, van Meurs R. 2015. Longest recorded underwater dive by a polar bear. Polar Biology 38: 1301-1304.

Stone IR, Derocher AE. 2007. An incident of polar bear infanticide and cannibalism on Phippsøya, Svalbard. Polar Record, 43: 171-173.

Styrishave B, Pedersen KE, Clarke O, Hansen M, Björklund E, Sonne C, Dietz R. 2017. Steroid hormones in multiple tissues of East Greenland polar bears (Ursus maritimus). Polar Biology 40: 37-49.

Tartu S, Bourgeon S, Aars J, Andersen M, Polder A, Thiemann GW, Welker JM, Routti H. 2017. Sea ice-associated decline in body condition leads to increased concentrations of lipophilic pollutants in polar bears (Ursus maritimus) from Svalbard, Norway. Science of the Total Environment 576: 409-419.

Thiemann GW, Derocher AE, Stirling I. 2008. Polar bear Ursus maritimus conservation in Canada: an ecological basis for identifying designatable units. Oryx 42: 504-515.

Towns L, Derocher AE, Stirling I, Lunn NJ, Hedman D. 2009. Spatial and temporal patterns of problem polar bears in Churchill, Manitoba. Polar Biology, 32: 1529-1537.

Towns L, Derocher AE, Stirling I, Lunn NJ. 2010. Changes in land distribution of polar bears in western Hudson Bay. Arctic 63: 206-212.

Tyrrell M, Clark DA. 2014. What happened to climate change? CITES and the reconfiguration of polar bear conservation discourse. Global Environmental Change 24: 363-372.

Vongraven D et al. 2013. A circumpolar monitoring framework for polar bears. Ursus 23: 1- 66.

Voorhees H, Sparks R, Huntington HP, Rode KD. 2014. Traditional knowledge about polar bears (Ursus maritimus) in Northwestern Alaska. Arctic 67: 523-536.

Whiteman JP, Harlow H J, Durner GM, Anderson-Sprecher R, Albeke SE, Regehr EV, Amstrup SC, Ben-David, M. 2015. Summer declines in activity and body temperature offer polar bears limited energy savings. Science, 349: 295-298.

Wiig Ø, Aars J, Born EW. 2008. Effects of climate change on polar bears. Science progress 91: 151-173.

York J, Dowsley M, Cornwell A, Kuc M, Taylor M. 2016. Demographic and traditional knowledge perspectives on the current status of Canadian polar bear subpopulations. Ecology and evolution 6: 2897-2924.

A PDF of this SI: harvey-et-al-bioscience-2017-supplementary-information

via Watts Up With That?

December 5, 2017 at 01:33PM

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