JACKSON HOLE, Wyo. — A recent reevaluation of how bears are counted has provided wildlife managers with a whole new perspective on the grizzly population, and has resulted in new numbers better reflecting what many have said all along: there are a lot of grizzlies out there.
When the Yellowstone Ecosystem Subcommittee (YES) asked the Interagency Grizzly Bear Study Team (IGBST) to reassess a technique (Chao2) used in annual population estimates, the IGBST went back to the drawing board. What they found were a couple of flaws in the way unique females with cubs-of-the-year were being counted.
Among some problems in the way the team was extrapolating out population based on sow and cub sets was an “underestimation bias associated with a distance criterion between sows with cubs.” Basically, when a female griz with cubs was spotted, and then another spotted days later, researchers were assuming the second spotting was the same bears if the distance between the sightings was within 30km. Turns out, a more reliable distance would be 16km.
That’s just one of the ways the IGBST came to the conclusion they have been undercounting bears all this time.
With improvements to Chao2 modeling, current estimates of the bear population have come up…significantly.
In 2020, there were as estimated 727 grizzly bears in the Greater Yellowstone Ecosystem (GYE). Using revised population estimation, the griz population today is probably closer to 1,069. That would be the most bruins ever counted by the agency, and begins to quantify what hunters, ranchers, and recreational users have been saying for some time: that the grizzly has recovered at this point, and might be bordering on over-populated for the available habitat.
Human-bear conflicts certainly have been on the rise in recent years as have been “problem bears,” relocations, and euthanizations. The implications of the new findings could be huge. Anecdotal evidence, now combined with hard numbers will undoubtedly heat up discussions of whether the grizzly has fully recovered enough to be removed from federal protection.
Wyoming—along with Idaho and Montana—has been pushing for delisting to bring bear management back to the state level.
