Study counts 600 black bears in Glacier Park
<p>A cinnamon-colored black bear feeds on grass and dandelions in Glacier National Park.</p>
A trio of researchers recently concluded that Glacier National Park’s black bear population is about 600 — roughly one black bear for every 2,167 acres.
The study, conducted by U.S. Geological Survey scientist Kate Kendall and colleagues Amy McCleod and Jeff Stetz, is based on nearly 1,800 black bear hair samples collected during a 2004 grizzly bear DNA study.
Researchers gathered hair samples using “bear traps,” with a scent station used to attract bears inside a barbed wire fence that snagged their hair, or by attaching small pieces of barbed wire to rub trees. Both grizzly and black bears select trees they regularly like to rub on. DNA in the hair follicles was analyzed to identify species and sex as well as individual bears.
The study was initially designed to estimate the grizzly bear population in Glacier Park and the Northern Continental Divide Ecosystem. But Kendall eventually was able to secure enough funding to look at the black bear population in the samples that were gathered in the Park. This is the first scientifically validated estimate for the black bear population and density in the Park.
Kendall said the study shows that the Park provides good black bear habitat and noted that the numbers are significant because black bears are sharing the Park with about 300 grizzly bears. Most black bears also do a remarkably good job of avoiding the 2 million humans who visit the Park each year.
When researchers removed areas of the Park not considered good black bear habitat, the density rose to a little more than one black bear per 1,857 acres. Black bears are generally not found in treeless and barren habitat. Black bears are much better at climbing trees than grizzly bears, which is one way they are able to elude the larger grizzlies that have been known to kill and eat black bears.
Kendall, who is now retired, continues to analyze bear hair data gathered exclusively from rub trees over the course of the past few years. The hope is to use that DNA evidence to determine population trends over time.
Currently biologists monitor population trends by capturing bears in traps, radio collaring them and then monitoring them to see how long they live and how many offspring they produce. A DNA study, if it proves valid, is easier on the bears as they’re never handled by humans.