Po­lar bears are not do­ing all right

The Daily Courier - - LETTERS -

Ed­i­tor: Jim Church has force­fully con­tra­dicted a key find­ing of a Na­tureServe Canada re­port, “On Guard For Them,” that po­lar bears are at-risk, “vul­ner­a­ble” to ex­tinc­tion if we don’t pro­tect them (Po­lar bear pop­u­la­tion is boom­ing, April 15).

Cit­ing the In­ter­na­tional Union for the Con­ser­va­tion of Na­ture (IUCN) and the U.S. Fish and Wildlife Ser­vice (USFWS), Church says both or­ga­ni­za­tions re­ported a 16 per cent in­crease in po­lar bear pop­u­la­tions world­wide be­tween 2005 and 2015.

He caps off his ar­gu­ment by point­ing to a Globe and Mail re­port of a Nu­navut gov­ern­ment sur­vey that he says found a 66 per cent in­crease in the bear pop­u­la­tion.

He sus­pects a con­spir­acy is afoot — that po­lar bears were added to the in­ter­na­tional at-risk list “for po­lit­i­cal pur­poses be­cause the data doesn’t sup­port such a dras­tic mea­sure.”

My re­search in­di­cates Church is wrong. The IUCN Red List of Threat­ened Species cur­rently as­sesses po­lar bears as “vul­ner­a­ble,” while the USFWS Species Pro­file for Po­lar bear as­sesses them as “threat­ened.”

The Globe and Mail makes clear that the Nu­navut sur­vey was con­ducted in 2012 and was con­cerned with es­ti­mat­ing the num­ber of bears along the western shore of Hud­son Bay. The es­ti­mate was 66 per cent higher than sci­en­tific mod­el­ling pre­dicted the pop­u­la­tion would be.

I could not find the sur­vey to learn more.

Ac­cord­ing to the Na­tional Post, a fol­low-up re­port by the Nu­navut gov­ern­ment was con­ducted this year. I went to the re­port it­self, which says that the bear pop­u­la­tion in Kane Basin was sta­ble or in­creas­ing, while in Baf­fin Bay, pop­u­la­tion trends were un­cer­tain due to “sev­eral lim­i­ta­tions” of the avail­able data.

The body con­di­tion in Baf­fin Bay po­lar bears had de­clined, how­ever, “in close as­so­ci­a­tion with the du­ra­tion of the ice-free pe­riod and spring sea ice tran­si­tion dates. This is con­sis­tent with the hypothesis that re­duced time on the sea ice (and pre­sum­ably de­clin­ing ac­cess to prey dur­ing spring to early sum­mer) is a pri­mary mech­a­nism driv­ing this de­cline.”

In other words, the Baf­fin Bay bears were skin­nier than they used to be. As for the Kane Basin bears, the sci­en­tists noted that if trends in di­min­ish­ing sea ice due to cli­mate change were to con­tinue, they would likely ex­pe­ri­ence sim­i­lar nega­tive im­pacts.

The Na­tional Post con­tacted re­search bi­ol­o­gist Ian Stir­ling, “a world-rec­og­nized ex­pert on all things po­lar bear,” for com­ment.

“The un­der­ly­ing con­cept is pretty sim­ple,” he said. “Bears need sea ice as a plat­form from which to hunt seals.”

Other food sources such as sea birds or ground squir­rels will not pro­vide the nu­tri­tion they need.

“The idea that they are just go­ing to adapt some­how to a largely dif­fer­ent eco­log­i­cal en­vi­ron­ment that they have been evolv­ing into for a few hun­dred thou­sand years is sim­ply un­re­al­is­tic wish­ful think­ing,” said Stir­ling.

We could safely con­clude that the Na­tureServe Canada re­port is cor­rect. If we don’t find a way of pro­tect­ing po­lar bears, they will be­come ex­tinct. Dianne Varga, Pen­tic­ton

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