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North America’s three bear species — blackbears, grizzly bears and polar bears — don’t typically live in the same place.But in Wapusk National Park, on the west coast of Hudson Bay in northernManitoba, we caught all three bears on camera — for the first time.


My colleagues and I began studying thebears in Wapusk in 2011, after more polar bears than expected began visitingnew field camps in the park. We used remote cameras — a widespread, economicaland non-invasive tool for studying wildlife — to find out why and when thepolar bears were visiting these camps.


But Wapusk also lies along the northernedge of the boreal forest, where black bears are well established. We saw themtoo, but we were surprised that their visits to our most southerly cameras, onthe Owl River, were almost as numerous as those by polar bears.


Grizzly bears visited all three study sitesalong the coast of Wapusk National Park. (Douglas Clark), CC BY-ND


What was new to us were the grizzlies. Itwasn’t just one or two transient bears, but several, and we suspect at leastone of them may be denning there.


What we’ve seen in Wapusk is consistentwith how researchers expect northern carnivore populations to respond toclimate change. The waking life of all bear species is governed by their needto accumulate fat stores for the next hibernation, so this overlap is mostlikely a response to changes in the availability of bear foods. Which foods, however,we don’t yet know.


Three polar bears walk past a camera trapin Wapusk National Park. (Douglas Clark), CC BY-ND


We also don’t know how these speciesinteract with each other, but we predict that grizzlies will benefit most sincethey dominate both other species elsewhere.


Grizzly bears have displaced and eatenblack bears and polar bears in other places, and polar-grizzly hybrids havebeen documented in the Northwest Territories. It’s clear that the potential forhybridization exists in western Hudson Bay too.


Change has become increasingly central inecological theory, and its implications have produced heated debate within theconservation community.


Black bears are well established in theboreal forest of Wapusk National Park.


This matters for the grizzly because itsexpansion into the Arctic has been portrayed as a threat to polar bears. Someargue such a threat should be removed.


In 1998, when I worked in Wapusk, I wastold by a manager to get rid of the first grizzly we saw. (I didn’t.)


Wapusk, however, is a co-managed park thataims to integrate scientific and traditional knowledge with human values. It isequipped for addressing these hard questions. And the question of how tonavigate increasing environmental variability more effectively — whilerecognizing the stakes local people have in these conservation decisions — isthe biggest challenge environmental managers face today.


This particular story of the three bearsisn’t over, and we don’t know how it will end. Consequently, we need to bring aheavy dose of humility to answering the scientific and societal questions thethree bears have handed us.