UMass studying effects of increasing moose population on
forests around Quabbin Reservoir

Published: Tuesday, May 08, 2012, 6:00 AM     Updated: Tuesday, May 08, 2012, 7:11 AM
Stan Freeman By Stan Freeman The Republican  Photo by Michael Beswick / The Republican
This moose heads into the woods in Belchertown early one morning in December.

Long absent from Massachusetts, moose have become abundant enough around Quabbin Reservoir that wildlife officials have grown concerned about the impact of one of North America’s largest wild animals on the watershed forests.

Moose, like deer, eat tree seedlings on the forest floor, and if the browsing is too heavy, there may not be enough young trees to replace older trees as they die.

A study is under way by a researcher at University of Massachusetts in Amherst to determine what effect the moose are having.

“Preliminary data,” says David Wattles, a doctoral candidate in the UMass Department of Environmental Conservation, “indicates that moose may be slowing – but not preventing – forest regeneration. But, it’s too early in the research to say if moose, at their current density, are having any long-term impacts.”

The project, funded primarily by the state Division of Fisheries and Wildlife, involves studying the habits and behavior of moose on the Quabbin watershed lands, a population estimated to be 100 animals, part of a statewide population of about 1,000.

Primarily a woodland animal, moose were extirpated from Massachusetts by the early to mid-1800s as much of the state’s forestland was converted to farms.

However, many of those farms were abandoned after the Civil War as agriculture shifted west. Open fields grew back to forest, and moose gradually migrated into the state from the north, with much of the population growth coming in recent years.

In 1998, the state’s moose population was estimated at 75. By 2006, it had grown to nearly 1,000.

Built in the 1930s, Quabbin Reservoir and its watershed were off limits to hunters for most of its history. However, finding that densities of deer were as much as five times higher on those lands than outside the watershed, and that young trees were not growing on the forest floor because of deer browsing, the state instituted a deer hunting season at Quabbin in 1991 to bring down those densities. Soon, deer densities there were in line with the rest of the state, and tree seedlings reappeared on the forest floor.

However, moose can eat perhaps 10 times as much in a day as a deer.

“If you go to a stand that was harvested 10 years ago,” Wattles said, “you’ll still see signs of recent browse and the impacts of older browse, but many of the saplings and young trees will have already grown well over your head and out of browse range for moose.”

“So are there impacts? Yes,” he said. “But moose aren’t in my opinion overly impacting regeneration, certainly not to the extent that deer did prior to the hunt in the (19)90s.”

“If you look at the end of winter, it seems (moose) have eaten everything in (an area cleared by logging),” said Wattles, “but by the end of summer, the regrowth is remarkable.” He believes the state’s moose population has, for the time being, stabilized at about 1,000 animals.

Thomas K. O’Shea, the assistant director of wildlife for the state Division of Fisheries and Wildlife, said a bill is introduced nearly every year in the state Legislature to establish an annual moose hunting season, and there is again such a bill this year.

“I would say we’re neutral on it. We’re waiting to see the research results,” he said. “There are a lot of questions about moose in the long term.”