An annual survey shows the moose herd in northeastern Minnesota continues to decline.
The Department of Natural Resources's aerial survey of moose found 4,900 animals in January, down from 5,500 the year before. The survey shows declines in both the number of calves and number of bulls in relation to the number of cows.
DNR forest wildlife group leader Mark Lenarz said the trend has been consistently downward since 2002.
"What we've seen is continued level of high adult mortality in the population and we've see high levels of calf mortality as well, and so you put the two of them together and it causes the total numbers to decline over time," he said.
It's not clear whether Minnesota will completely lose its moose population in the near future.
"If we get into a run of good years, then the population could stabilize out," he said. "It's like trying to predict the weather. It's really difficult to know what's going to happen in the next ten or twenty years."
The DNR says most deaths are from unknown causes, but disease and parasites are suspected. It's possible climate change is stressing the state's moose.
The Legislative-Citizen Commission on Minnesota Resources is recommending a study next year to focus on the factors behind high moose mortality.