Braving sub-zero temperatures to go winter camping in Montana's Glacier National Park used to have one big perk - no need to watch out for grizzly bears. The bears usually hibernate from late-November to April. But now, say biologists, two or three young grizzlies are on the prowl year-round in the park, pilfering the kills of wolf packs and mountain lions.


Wolf researchers in the park found fresh grizzly tracks throughout January and February in the vicinity of wolf and lion kills. "It's actually been several winters running that the bears have been taking advantage of the opportunities afforded by other carnivores," says park spokeswoman Amy Vanderbilt. Ever since wolves from Canada migrated into the park about 10 years ago, the winter food supply for grizzlies has increased.


To cope with the uninvited dinner guests, lions in the park are changing their eating habits, say biologists. Rather than dilly-dally around a deer carcass for a few days, lions immediately chow down their kills.


The new dynamic appears to be limited to the park. South of Glacier, along the South Fork of the Flathead, grizzlies are hibernating as usual. The reasons, biologists say, are lower big-game populations and fewer lions and wolves.


* Mark Matthews