More bears, thou­sands more teeth to sort

The Denver Post - - NEWS - By Pa­trick Whit­tle

BRIDGTON, MAINE» Carolyn Nistler is at the fore­front of a boom in a re­source that plays a key role in the man­age­ment of Amer­i­can wildlife: bear teeth.

Nistler, owner of a Mon­tana lab, and oth­ers are sort­ing through a wind­fall of teeth taken from Amer­i­can black bears, which use their pow­er­ful jaws to crush hazel­nuts and chew sal­mon flesh. The grow­ing pop­u­la­tion of the bears in the United States has sci­en­tists sort­ing through thou­sands more teeth, which are im­por­tant to get a han­dle on the health of Amer­ica’s bru­ins.

“Pop­u­la­tions are grow­ing,” she said. “We’ve in­creased fa­cil­i­ties to ac­com­mo­date so turn­around time isn’t longer.”

States use bear teeth for re­search about met­rics such as how old the an­i­mals were at the time they died, which can be an in­di­ca­tor of how healthy bear pop­u­la­tions are. The teeth are most of­ten har­vested from bears killed by big game hunters, who seek the burly an­i­mals for sport all over the coun­try. Some are also taken from road­kill an­i­mals.

Nistler owns Mat­son’s Lab­o­ra­tory in Man­hat­tan, Mont., which pro­cesses the most teeth of any lab in Amer­ica. The lab con­tracts with state wildlife de­part­ments and pro­cessed nearly 260,000 black bear teeth from 2009 to 2016, up from fewer than 220,000 from 2001 to 2008, ac­cord­ing to data pro­vided by Nistler.

A grow­ing bear pop­u­la­tion has cre­ated more hunt­ing op­por­tu­ni­ties, which leads in turn to more bear teeth for re­searchers, Nistler said.

In­deed, the tooth boom comes as the black bear pop­u­la­tion is ex­pand­ing in many states, es­pe­cially in East Coast states such as Maine, where the pop­u­la­tion has grown from 30,000 in 2010 to more than 35,000 now ac­cord­ing to state wildlife man­agers. Bear pop­u­la­tions also are grow­ing in Mas­sachusetts, New Jersey and else­where. Black bears live in 41 states.

The na­tion­wide pop­u­la­tion was more than 400,000 in 2008, which is most likely dou­ble the pop­u­la­tion in 1900, and it has ex­panded even more in the past nine years, said Lynn Rogers, a bear ex­pert with the North Amer­i­can Bear Cen­ter in Ely, Minn.

Bear pop­u­la­tions have in­creased as peo­ple have learned to live around the an­i­mals, which are mostly skit­tish around hu­mans, Rogers said.

“As at­ti­tudes change, they are com­ing back,” he said. “They just go about their busi­ness of for­ag­ing.”

Jen­nifer Vashon, a bear bi­ol­o­gist with the Maine De­part­ment of In­land Fish­eries & Wildlife, said the grow­ing num­ber of teeth will pro­vide state wildlife man­agers with im­por­tant data, as anal­y­sis of the teeth is a way to get an idea of how many young bears there are in states. Hunters in Maine, who pur­sue the an­i­mals over bait or with hunt­ing dogs in the state’s vast wilder­ness, are re­quired to re­move a tooth from ev­ery bear they kill.

The teeth are sec­tioned and viewed un­der a mi­cro­scope, mak­ing it pos­si­ble to de­ter­mine the age of the bear by count­ing rings sim­i­lar to those on a tree stump, Vashon said.

“An­other ben­e­fit of col­lect­ing teeth is pro­vid­ing in­for­ma­tion to the hunter about the age of the bear they har­vested,” she said.

Nistler and Vashon said the vol­ume of teeth isn’t re­sult­ing in an un­man­age­able back­log of teeth, but it does re­quire a lot of work. The lag time be­tween sub­mit­ting teeth and get­ting the re­sults is typ­i­cally about eight or nine months, Vashon said.

The lag causes some anx­i­ety among hunt­ing guides, who rely on up­dated wildlife data as part of their work, said Don Kleiner, ex­ec­u­tive di­rec­tor of the Maine Pro­fes­sional Guides As­so­ci­a­tion. At the same time, guides un­der­stand that pro­cess­ing thou­sands of teeth takes time, he said.

“I hear some com­plain­ing from my guys that they don’t know about the bears from a year ago,” Kleiner said. “But 3,000 teeth have to be seg­mented and looked at un­der a mi­cro­scope.”

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