How Many Grizzly Bears Live in Yellowstone Country? - My Yellowstone Park

How Many Grizzly Bears Live in Yellowstone Country?

In 2014/2015 the answer is: less than 1,200. That seems to be the only number that people can agree on.
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A grizzly bear near Yellowstone's Swan Lake. Photo by NPS Neal Herbert

A grizzly bear near Yellowstone's Swan Lake. Photo by NPS Neal Herbert

The answer is: less than 1,200. That seems to be the only number that people can agree on.

Yellowstone Grizzly Bear Investigations 2014: Report of the Interagency Grizzly Bear Study Team

The U.S. Geological Survey just published a report in September, 2015 (http://nrmsc.usgs.gov/files/norock/products/IGBST/2014Report.pdf). It estimated the grizzly bear population at 757 bears in 2014. This is not an exact number and has been calculated based on confirmed sightings of 119 grizzly sows with cubs. The actual estimate is a range from 674 to 839 total grizzly bears.

Van Manen, a team leader with the Interagency Grizzly Bear Study Team, said,"we are underestimating probably by about 40 percent, according to these calculations." The model that federal bear managers use to gauge grizzly numbers, called a “Chao2” estimator, is biased low. Adjusting for the model's underestimation, the grizzly population would have come in this year at around 1,000. Some say 1,200.

Then on November 3-4, 2015, about a month after the report was issued, wildlife biologists met in Teton Village and estimated the current 2015 population had decreased to 714. Even though this is a reduction of 6%, Van Manen said the new grizzly bear population estimate is a single-year snapshot and not any indication that the population is in decline.

Yellowstone Country Defined

There are 54 defined bear observation areas including inside Yellowstone and Grand Teton National Parks, and in surrounding areas including Cody, Jackson and Lander, Wyoming, and areas north and west of Yellowstone in Montana. See the map below of sow sightings. The green lines indicate the national park boundaries.

Map of Grizzly Study Area in Yellowstone.

Should Grizzlies Be Delisted?

All of these bear numbers play a political role.

In 1975, at an estimated population of 200, grizzly bears were added to the list of animals receiving Endangered Species Act protection. Only two years since, have these protections been lifted, allowing legal hunting.

During the November meeting, U.S. Fish and Wildlife Service said that there were no current plans to propose a rule that could lift protection for grizzlies. However, they are penciling in a meeting date in February 2016 in case they need to discuss this very change.

Wildlife preservationists say the numbers are not large enough to trigger the end of protection. Delisting advocates say that as grizzly populations have increased, bears are increasing their habitat zones and are coming in conflict with humans more often. Indeed, Van Manen stated that 90% of the 52 grizzly bear deaths in 2015 were because of human interaction.

This potential delisting would be on the heals of a fatal grizzly attack of a hiker in Yellowstone, where the sow was killed and the cubs sent to a zoo. It gained international attention with mostly criticism on punishing an animal for doing what comes natural. If the protection for grizzlies was lifted and hunting resumed, it could be seen as a black eye for Wyoming.

Related

Grizzly bear in Yellowstone. Photo by Jake Davis.

Grizzly bear deaths in Yellowstone

A recent study by the Interagency Grizzly Bear Study Team finds that 10 of the 16 grizzly bears that have died so far this summer in Yellowstone National Park have died of natural causes.

Grizzly Bear at Swan Lake Flats. Photo by NPS Jim Peaco

Should Grizzly Bears be Delisted?

April 17, 2008: There are all kinds of answers to the question of whether the grizzly in the lower 48 is doing well enough to no longer require protection.