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Some griz­zly bears for­age for food around ar­eas of hu­man ac­tiv­ity. But how do they learn to do so, na­ture or nur­ture? An­drea More­house has an an­swer.

Canadian Wildlife - - FEATURES - By Cana­dian Wildlife Staff

Some griz­zly bears for­age for food around ar­eas of hu­man ac­tiv­ity. But how do they learn to do so, na­ture or nur­ture? An­drea More­house has an an­swer.

Back in Septem­ber, a fam­ily in south­ern Alberta spot­ted a trio of young griz­zly bears wan­der­ing onto their farm, west of Pincher Creek. It wasn’t an en­tirely new ex­pe­ri­ence. The fam­ily had spot­ted griz­zlies in pas­tures on their prop­erty be­fore. But this group was more brazen. In­stead of stick­ing to the pas­tures, they started com­ing to­ward the houses, pay­ing spe­cial at­ten­tion to a pen of pet ducks.

The fam­ily started mak­ing noise, yelling and lean­ing on the horn of a truck. The bears ig­nored them at first, then even­tu­ally took the hint and mo­seyed off. But they didn’t run or walk away quickly, as other bears had done in the past.

For An­drea More­house, a bi­ol­o­gist at the Univer­sity of Alberta, this kind of en­counter — known to re­searchers as a “con­flict in­ci­dent” — raises an im­por­tant ques­tion for griz­zly man­age­ment: not all bears go nos­ing around prop­erty, raid­ing grain bins or, some­times, prey­ing on live­stock or pets, to find food. In those that do, is it a learned be­hav­iour or one that’s passed on ge­net­i­cally?

More­house says an­swer­ing that ques­tion is im­por­tant; it will help wildlife of­fi­cials and com­mu­ni­ties de­velop mea­sures to pre­vent such con­flicts — for the good of both bears and peo­ple. More­over, she says research she re­cently con­cluded pro­vides strong ev­i­dence

that young cubs learn the be­hav­iour. It’s the re­sult of nur­ture, not na­ture.

To ar­rive at this con­clu­sion, More­house and her team cre­ated a data­base track­ing the ge­netic lin­eage of more than 2,000 in­di­vid­ual griz­zlies in a sub-pop­u­la­tion that cov­ers south­ern Alberta, south­east­ern Bri­tish Columbia and north­ern Mon­tana. “Es­sen­tially, we built a fam­ily tree and com­pleted a parent­age anal­y­sis,” she says.

Next, More­house’s team col­lected hair sam­ples around con­flict sites in Alberta to de­ter­mine which bears could be iden­ti­fied as prob­lem bears. “We looked at those Alberta bears that had been in con­flict and those that hadn’t,” More­house says. “Then we looked to see who their moth­ers were and who their fa­thers were, and whether their moth­ers or fa­thers had been in­volved in con­flicts.”

More­head’s team found that the over­whelm­ing pro­por­tion of bears in­volved in con­flicts were also the off­spring of moth­ers that dis­played con­flict be­hav­iours. The fa­thers? Not so much. Thus, the re­sults of the study are strong ev­i­dence that con­flict be­hav­iours are learned be­hav­iours, passed on from mother to cub dur­ing the two or so years young griz­zlies stay with their moth­ers. (Griz­zly fa­thers are not in­volved in rais­ing off­spring.)

The find­ing is sig­nif­i­cant be­cause it helps wildlife of­fi­cials de­velop bet­ter strate­gies for man­ag­ing griz­zly bears, which have been listed as a threat­ened species in Alberta since 2010.

“One of the big­gest man­age­ment take-homes from this work is that it re­ally high­lights the im­por­tance of try­ing to be proac­tive,” More­house says. She points to mea­sures such as re­design­ing grain bins, a com­mon tar­get of bears look­ing for food at farms, so that they are more like the bear-proof garbage cans found in many parks.

Elec­tric fenc­ing can also dis­cour­age bears from for­ag­ing around places where hu­mans live or work. Such de­ter­rents re­duce the op­por­tu­nity for young bears to learn to as­so­ciate peo­ple with food, re­duc­ing the like­li­hood they’ll de­velop con­flict be­hav­iours them­selves. With her study com­plete, More­house is now work­ing with com­mu­ni­ties on strate­gies to help en­sure bears don’t de­velop those be­hav­iours.a

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