A study of moose calves born in northern Minnesota last May had some sobering results. It showed a 60 percent decline in the state's moose population over the past five years.
Researchers met at a Minnesota Department of Natural Resources round table in Bloomington this weekend to discuss potential causes.
The DNR collared 49 calves last May and to track their survival, said Ron Moen, a biologist at the University of Minnesota-Duluth.
"By September, there was a 70 percent mortality rate, and that's high...what we're seeing now is on the order of 20 to 35 calves per 100 cows in winter surveys, historically, that was on the order of 35 to 45--with variation. But that's the kind of decline you need to consider," he said.
Most of the young calves were killed by wolves, and some very young ones were killed by bears, but the high predation rate could indicate weakened adults were less able to defend their young, he said.
Moose populations across the U.S. and southern Canada have become increasingly vulnerable to ticks and parasites with climate change and loss of habitat.