University of Alberta biologists who spent 10 years monitoring 112 bears in the province report warmer temperatures and easier access to food associated with forest disturbances helped the grizzlies to build more body fat, known to increase the chances of successful reproduction for mothers.
Bears born in such favorable conditions have a head-start in life, Alberta biologist Scott Nielsen said.
"Understanding variations in body size helps us understand what limits grizzly populations," he said. "We get clues about the environments that most suit grizzlies by examining basic health measures such as body size.
"A simple rule is, the fatter the bear, the better."
With only about 750 of the frizzy bears in the province, half of them adults, the provincial government has classified them as a threatened species.
In years when warmer temperatures and less late winter snow brought on earlier spring conditions, the average body size of bears as adults was larger, the researchers said.
"We hypothesize that warmer temperatures in this ecosystem, especially during late winter and spring, may not be such a bad thing for grizzlies," Nielsen said, as rising temperatures would "lengthen the growing season and the time needed to fatten prior to hibernation."