Maine's state animal - the moose - fared better with potentially deadly ticks this past winter than in previous years, but the herd remains imperiled by the parasites in northern New England and beyond, wildlife biologists said.
Moose calf mortality in the state, which has the largest moose population in the continental United States with an estimated 60,000 to 70,000 animals, dropped from 73 percent to 60 percent this year, state biologist Lee Kantar said. Adult moose did even better, with mortality falling from 33 percent to 8 percent in that time, he said.
The finding comes as Maine and New Hampshire are in the midst of a five-year study to better understand why their moose populations are in decline. Both states, and others including Vermont and Minnesota, have cited winter ticks as a key driver of moose deaths.
"While we are encouraged by the difference between year one and two, we should expect variability over time," Kantar said.
Thousands of ticks are sometimes found on one moose, and the parasites can bleed the animals and cause anemia and death. States have cut back on moose hunting permits as a result. Maine is issuing its fewest number of moose permits in 12 years this year.
Recent warm winters have allowed the ticks to thrive, scientists have said. Warm fall temperatures and early spring snowmelt create ideal conditions for more ticks to survive the winter and lay eggs.
Kristine Rines, a wildlife biologist for New Hampshire, said state officials hoped the winter wasn't as bad for ticks as previous years, but new data suggest it was. Officials in the state said 20 of 27 moose calves tagged by state biologists had died by late April, compared to 13 of 22 last year.
"Things were looking a little promising but in the end the ticks got them anyway," Rines said.
Vermont biologists said they aren't sure yet how their state's moose population fared. All three northern New England states have seen heavy moose population loss in recent years. Maine's fell to its current level from 76,000 in 2012 while New Hampshire's has dropped from 7,600 in 1996 to 4,000. Vermont's herd has been halved from 5,000 in 2006.
Maine plans to reduce hunting permits nearly 10 percent, to 2,815, this year. New Hampshire this week dropped the number of moose hunt permits from last year's 124 to 105 for this hunting season. Those numbers compare to a high of 675 permits issued in 2006 and 2007.
Elsewhere in the country, Minnesota regulators say their state's moose population is down about 60 percent from a 2006 estimate of 8,840, and the moose hunt is currently suspended.
Kantar said biologists will need to look at multiple years of data to determine if this year's lower death rate in Maine is a trend or an outlier. He said the state's moose herd estimate for 2015 is not yet complete.
Associated Press writer Rik Stevens contributed from Concord, New Hampshire.