Wildlife Refuge to count Brown Bear population

Posted: Thursday, June 03, 2010

The Kenai Wildlife Refuge began an operation to count its brown bear population by hair sampling and genetic testing last Tuesday.

Photo By M. Scott Moon
Photo By M. Scott Moon
A yearling brown bear rolls around on its back near the Russian River last spring. Wildlife biologists are hoping to get a better handle on how many of the bears are on the Kenai Peninsula.

Refuge wildlife biologist John Morton said that this study will help the government determine the survivability of Kenai Peninsula's previously uncounted bear population. Before this month-long study, the refuge had estimated the Peninsula's brown bear population by multiplying the average population of the animals found in similar regions by the refuge's total square footage, Morton said.

"We don't have any kind of empirical data. The results are going to be interesting," he said.

Morton said that the refuge set up nearly 200 sites with strands of barbed wire that form a triangle around a dug up pile of trees and top soil, all laced with brown bear lure.

The wire will snag the bear's hair, which contains its genetic code, when it lumbers towards the simulated food cache. The bruin won't find food, but three liters of cattle blood and fish oil, which the biologist said smells like a corpse.

"It looks like a bear buried a moose carcass," he said.

The false food caches are set up away from populated areas and clearly marked, according to Morton. Officials will collect hair from the lures every five days over the month-long period, he said, and test them for genetic markings. Morton said that the survey will use the individual gene signatures to estimate the population.

Although the study underwent trials runs in 2004 and 2006, Morton said that the refuge will use the results of the $500,000 census to plan similar operations in the future. He estimated that the census population could be off by up to a quarter.

"It's not an end-all survey," he said. "It's a beginning."

Morton considered using breakaway snares to collect hair instead of barbed wire. He decided against it because those survey techniques cost up to $2 million more and primarily are used along salmon streams.

According to Alaska Fish and Game Department biologist Jeff Selinger, a census hasn't been taken in the past because of the cost. He believes the study will give a valuable estimate if samples containing follicle are collected regularly.

"It's a very accepted technique in the brown bear world," the biologist said.

Coastal agencies have used aerial counting methods to determine their brown bear population, Morton said. But the refuge's abundant tree life makes it difficult to reliably count the population. Selinger said that the dense forest makes tagging the animals tough, as well.

"You can't use a mark and capture census because of the high vegetation," he said.

The weather can affect the quality of the hair samples though, he said. According to the biologist, humidity degrades the quality of the samples, which need to be dried before testing.

DNA hair testing only reveals the gender of the bears as well, Selinger said, which hinders biologists ability to determine the survival rate of female brown bears.

"You can come up with a gender distribution," he said. "But no age."

Tony Cella can be reached at 335-1242.

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