Billings, Mont. – Bear biologists counted fewer females with cubs in and around Yellowstone National Park this year than they have since 1997, but they say it’s not an indication that the population is declining.
Wildlife officials estimate that 400 to 600 grizzlies live in the Yellowstone ecosystem, enough to warrant removing them from the endangered species list. An expected delisting proposal has not yet been released.
Counting the pairs helps biologists gauge the success of the Yellowstone population.
This year, biologists spotted 31 pairs, according to figures released Tuesday.
They observed an average of 43.6 pairs during the previous five years, including a high of 52 in 2002 and 49 last year. The last time they counted only 31 pairs was in 1997.
The dip doesn’t necessarily mean the population is shrinking, said Mark Haroldson, a biologist for the Interagency Grizzly Bear Study Team, a group of government scientists based in Missoula.
“It’s not a big red flag right now,” Haroldson said.
Other factors likely contributed to the low number, including a “bumper crop” of cubs in recent years that left many females unable to breed, and persistent snow at some feeding sites that kept away bears that otherwise would have been counted.
The numbers probably will rebound next year, said Chuck Schwartz, who led the study team.
Schwartz said several factors determine the health of grizzlies, such as the amount of habitat and food available and the rate at which the bears are killed by human activities.
“When you put these things all together, then you get to see a picture,” he said.
