Grizzly Bears: Fierce Predators, Natural Pole Dancers?
Watch out, strippers—grizzly bears have a knack for pole dancing. YouTube has a number of videos featuring the enormous creatures getting’ down to a variety of tunes. While rubbing up against trees, the bears rock their shoulders, raise their front legs overhead, and swing their hips from side to side while bending their hind legs, slowly moving down toward the ground then back up. The footage, it turns out, comes from a scientific endeavor—the Northern Divide Grizzly Bear Project in Glacier National Park. Katherine Kendall, of USGS’s Glacier Field Station, explains the project, and what, exactly, the bears are doing.
The bear really seems to enjoy the rub. Is this typical behavior?
The bears really do look like they enjoy rubbing on trees and rubbing their neck and rolling in the scent lure that we use to attract them to hair traps. We see this behavior in many of the remote photos and video we've gotten. We don't know a lot about why bears do this but assume that it serves as a form of chemical communication among species.
The footage is fantastic, especially with the music. When was it taken, and how did it end up online?
We have installed remote cameras at hair traps and natural rub trees for the past 4 years. My employer, USGS, posted a few of our early video clips on YouTube last year. Versions have proliferated with various combos of clips and music. You can see many more interesting and amusing clips (without music) on my website.
What are you hoping to learn from recording the bears?
We set up video and still cameras with motion sensor triggers to learn about bear behavior at our hair collection sites. This helps us design more efficient hair collection devices and learn how different sex/age classes of bears use these sites. We also learn about non-target species in these areas, such as the number of wolves in a pack and grizzly bear/black bear and wolf/bear interactions. The hair we collect at hair traps and rub trees, genotyped to identify the species, sex and individual identity of the bears, is used to determine population size, trend, distribution and genetic health.
Did you know much about the bears before the study?
The bears in the video are not known to us until we genotype the hair to identify them. We collected 34,000 hair samples at 2,560 hair traps and 4,800 bear rub sites over 8 million acres in northwest Montana and estimated the size of the grizzly bear population was 765. This area ranges from the Canadian border almost to Missoula MT, 180 mi to the south and includes Glacier National Park, 5 wilderness areas, 5 national forests, and 2 indian reservations. We covered all occupied grizzly bear habitat in this ecosystem. Incidentally, this was the grizzly bear DNA project that John McCain cited repeatedly in his campaign as an example of government waste.