Grizzlies: Shed and Be Counted
DNA samples taken from grizzly bear hair may help resolve a bitter dispute over the size of the bear population in and around Wyoming's Yellowstone National Park. Last month, federal scientists released a preliminary count of bears in the Yellowstone Lake area based on hairs trapped on streamside barbed wire fur catchers. The figure--84 individuals, compared to 44 estimated in the 1980s from bear tracks--shows that "we have a much more sophisticated technology" for tracking bear numbers, says Chuck Schwartz, head of the Interagency Grizzly Bear Study Team.
Schwartz now wants to do a Yellowstone-wide hair study to help pin down grizzly population trends--information that could prove pivotal in the hot debate over whether the animals are prospering enough to be removed from the U.S. endangered species list (Science, 23 April 1999, p. 568). A similar new study in Montana's Glacier National Park proved useful, but it's "not an inexpensive proposition," Schwartz says. A baseline bear count could cost $1 million, with more surveys needed to establish whether the Yellowstone population is growing or shrinking.