Like I said  ,he 'might have' , but he didn't. My point is the bears population seems to steady to growing despite all the hysteria around recent yearly fluctuating ice .The  historical evidence  demonstrates the species has had the ability to survive for over the last 500K years ,ice or no ice.
Of course ,not everybody agreed with his paper.
see: Stirling and Derocher’s sea ice trick – omitting facts to make polar bears appear endangered @ polarbearscience.com/2013/03/06/stirling-and-derochers-sea-ice-trick-omitting-facts-to-make-polar-bears-appear-endangered/
Was there a rebuttal to the rebuttal?