By MIKE STARK
Billings Gazette Friday, September 15, 2006

BILLINGS, Mont. — Bear biologists this year spotted a higher-than-
average number of female grizzlies with cubs in and around
Yellowstone National Park.

The annual tally is one of several ways wildlife officials gauge the
overall health of the grizzly population.

In 2005, only 31 females with cubs were counted, the lowest since
1997. This year, 46 were recorded, a few more than the average over
the past 10 years.

Chuck Schwartz, leader of the Interagency Grizzly Bear Study Team,
said the fluctuation isn’t surprising. One year, there may be a
bumper crop of cubs, followed by other years when female bears aren’t
available for breeding.

“It bounces around because of the biology of the species,” Schwartz
said, adding that it’s important to focus on overall trends rather
than the results of a single year.

There are an estimated 600 bears in the Yellowstone ecosystem, which
includes the national park and surrounding areas. But because bears
tend to live in remote places, it can be difficult to get an accurate
census.

That’s one of the reasons why biologists look at several factors to
gauge the population’s health, including the number of females with
cubs, how much land they occupy and have available, how much food
there is to eat and the rate at which grizzlies, especially females,
die because of people.

Schwartz said Yellowstone’s grizzly population seems to be holding
strong.

“All the monitoring indices that we’ve got this year fall right in
line with what we’ve seen in the past,” Schwartz said.

One of the wild cards, though, is a tiny nut that’s an important
snack for bears.

The nut of the whitebark pine, a knobby tree that grows at high
elevations, provides important fat and protein for bears –
especially in the fall, as they enter a feeding frenzy before
winter’s hibernation.

Bears get the seeds by raiding caches made by red squirrels.

When the trees provide a good crop of nuts — as they are this year –
grizzly bears tend to spend more time snarfing them at high
elevations and staying out of low-lying areas where they’re more
likely to run into trouble with people.

Studies have also shown that females bears that eat a lot of the
seeds produce more cubs per litter and reproduce more often.

But in recent years, whitebark pine trees have come under attack by
the mountain pine beetle, a native insect that has been experiencing
a major outbreak.

Last year, scientists estimated the beetles had killed nearly 720,000
whitebark pine trees in the Yellowstone ecosystem in one of the
largest infestations on record. It appears the beetles are hitting 30
to 40 percent of the trees, Schwartz said.

There have been severe outbreaks before, but some entomologists
believe the latest outbreak is connected to the Earth’s warming
climate, which could mean it will last for years.

It’s an open question how the decline of that food source might
affect grizzly bears.

“It’s certainly something that we’re concerned about,” Schwartz said.

Kerry Gunther, Yellowstone’s lead bear biologist, said there are
millions of whitebark pine trees and no indication that the increase
in bug-killed whitebark pines is having an effect on the park’s bears.

“There are probably more nuts out there than the bears could ever
eat,” Gunther said.

Late last year, the U.S. Fish and Wildlife Service recommended that
the grizzly bear be taken off the endangered species list. Some have
praised the proposal as a well-earned step in the long recovery of
grizzly bears. Others oppose it, saying there are still too many
threats facing bears, including limited habitat, declining food
sources and human development.

Fri Sep 15, 2006 5:28 pm

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Biologists count more bears
By MIKE STARK Billings Gazette Thursday, September 14, 2006 [oas:casperstartribune.net/news/wyoming:Middle1] BILLINGS, Mont. — Bear biologists this year… Sabrina
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