Biologists in New Hampshire and Vermont detailed another tough year for moose populations being challenged by infestations of winter ticks and presented the plans for the upcoming moose hunting seasons.
After a mostly stable 2019-2020 winter for moose, which then benefited from an early winter, the winter of 2020-2021 was less than ideal.
“Moose in northern New Hampshire had moderate to high infestations of winter ticks during winter 2020-2021,” said Henry Jones, moose biologist with the New Hampshire Fish and Game Department. “Due to blood loss from these winter ticks, we estimate there was substantial mortality (50 percent or greater) of 10- to 12-month-old calves in March to May and adult cows were in poor condition resulting in low production of calves in May.”
Currently, New Hampshire’s moose population is estimated at 3,500 animals statewide, with most of the population in the White Mountains north, he said.
The historic population high in New Hampshire had been 7,000 to 8,000 moose.
Although radio collar GPS studies were discontinued in New Hampshire several years ago, moose populations are still being monitored.
“We monitor the health of the population with biological data collected from harvested moose and a March snow-urine survey,” said Jones. “Harvested moose provide data on weight, productivity (the number of calves a cow will produce), and winter tick infestation levels. The March snow urine survey provides data on late-winter calf survival, which relates to winter tick infestation levels.”
Ongoing research since 2014 with the University of New Hampshire using more than 200 radio-marked moose is being concluded with data analysis by post-doctoral researcher Alexej Sirén.
“The analysis is focused on how to measure winter tick abundance and population health without radio-marking moose,” said Jones.
New Hampshire Fish and Game is also partnering in a regional initiative led by the U.S. Geological Survey, Vermont Cooperative Wildlife Research Unit, to monitor moose health and abundance, he said.
Warmer and shorter winters in recent years have led to a longer active season for winter ticks, which can attach to moose in the tens of thousands, resulting in high mortality for calves that can’t withstand the blood loss and greater emaciation and lower reproductivity for cow moose that are weakened.
Jones spoke of future population projections in New Hampshire.
“The population is still declining, but there has been some stabilization in the last five years,” he said. “As winter tick infestations are still moderate to high in some years, the population is expected to continue declining until the weather changes (longer winters return) or we reach moose densities that limit winter ticks.”
The number of moose hunting permits is based on the current moose population in New Hampshire’s 22 wildlife management units.
New Hampshire’s 2021 moose hunting season, which lasts a total of nine days, from Oct. 16 to Oct. 24, will offer fewer permits.
“There are 42 moose hunting permits issued for the fall 2021 season, which is a reduction of nine permits from 2020,” said Jones. “This is due to hunting permit issuance suspension in the central and southwest Moose Management Regions (areas just south of the White Mountains and southwest New Hampshire) as the population estimates for these areas reached a pre-determined cut-off level. Permits will be reissued if the population grows above the cut-off level.”
Permit issuance in northern New Hampshire (north of the Whites) could be increased in future years to manage for a lower moose density that will result in healthier moose with fewer winter ticks, a strategy that is currently being explored in Maine and Vermont, he said.
For the 2021 hunting season in Vermont, which didn’t have a moose season in 2019 and only allowed 55 hunting permits for its Wildlife Management Units E (E1 and E2) in the Northeast Kingdom in 2020, Vermont Fish and Wildlife Department is recommending to the Vermont Fish and Wildlife Board a combination of 60 either-gender and antlerless-only hunting permits in the Northeast Kingdom, with the expected harvest of about 58 moose including 20 to 30 adult females, or about 5 percent of the moose population in the Kingdom.
The goal, said Vermont biologists, is to reduce the moose population and thereby reduce winter tick abundance.
“Moose population reduction will be necessary to break the winter tick cycle and improve the health of moose in this region,” they said.
In the Vermont Fish and Wildlife Department’s recommendation, biologists said a three-year study that began in 2017 of 36 cows and 90 calves concluded that chronic high winter tick loads caused poor moose health in the Kingdom, and while adult survival remains relatively positive, impacts of winter ticks have caused birth rates to be very low and about half of moose calves die each winter from heavy tick loads.
Vermont’s moose archery season will run from Oct. 1 to Oct. 7 and the regular season from Oct. 16 to Oct. 21.
In Vermont, the moose population is estimated at under 2,000, down from a high of about 5,000 in the mid-2000s.
Most of Vermont’s moose are in the Northeast Kingdom.