SPRINGFIELD, Mass. – When more than a dozen lambs and sheep were slaughtered on a Shelburne farm last fall, wildlife officials suspected either a wolf that had escaped from captivity or a rogue mutt on a hungry rampage.
But after the culprit animal was killed and examined, they found themselves with a bigger mystery: How did a wild eastern gray wolf, an endangered species absent from the state for more than a century, find its way to western Massachusetts?
Thomas J. Healy, head of the U.S. Fish and Wildlife Service's Northeast regional office, said Tuesday recent DNA tests at the agency's Oregon labs confirmed it is the first gray wolf found in New England since a 1993 case in upstate Maine.
The discovery of the 85-pound male wolf may help solidify experts' theories that the endangered species has been migrating south from Canada and repopulating rural parts of New England.
This wolf, though, was found farther south than any other reported spottings, and nothing indicates it had escaped or been set free by someone keeping it as a pet, authorities said.
"This posed more questions than it answered," Healy said. "The only thing we were able to answer was that it was an eastern gray wolf. The history of where it came from and how it got here, we may never know."
According to the Massachusetts Division of Fisheries and Wildlife, the wild gray wolf was considered extinct in Massachusetts by about 1840. One was recorded in Berkshire County in 1918, but was believed to have escaped from domestic captivity.
A handful of confirmed spottings have been reported over the past decade of wolves being found in parts of Maine, Vermont and New Hampshire, but determining if they were wild or had been kept as illegal pets was difficult.
New England's large stretches of interconnected woods, mountainous regions and rural farmland offer good north-south corridors for wolves on the move.
Shelburne, about 8 miles west of Greenfield in Franklin County, is one such area. It is surrounded by miles of state forests, ski areas and open acreage.
The wolves disappeared from much of the northeastern United States by the late 19th century, but ideal habitat for the animals remains in remote parts of Maine, New Hampshire and New York's Adirondack mountains.
Wolves can travel hundreds of miles as they wander from where they were born, seeking food, mates and new territory.
If this wolf originated in Canada, the experts say, it likely crossed the St. Lawrence River in Quebec, went through Maine, then navigated hundreds of miles of roads, rivers and communities before reaching Shelburne.
"I'm a little bit flabbergasted, but that being said, when it comes to wolves, never say never," said Peggy Strusacker, a Vermont-based wolf expert with the Natural Resources Defense Council.
"Wolves always make us eat our words, wild wolves particularly."
Massachusetts state biologists visited Shelburne last October to check the sheep farmer's reports, which came a few weeks after another nearby farmer reported losing sheep and rams to an unknown predator.
Healy said the farmer did not kill the wolf, but that someone else — whom Healy would not identify — shot it one day after the biologists visited. Then, local wildlife officials examined it and turned it over to federal authorities.
Gray wolves usually eat deer and moose, but will adapt to eat other animals if necessary. Indeed, bits of lamb, bone fragments and tufts of wool were discovered in the Shelburne wolf's stomach after it was killed.
Todd K. Fuller, a professor of wildlife conservation at the University of Massachusetts-Amherst, was among the experts who examined the carcass.
He said the wolf was large for its species and probably was young because it had no obvious signs of disease, hair loss, tooth damage or other age-related problems.
"I think once they get to Maine, it wouldn't be that unusual," he said of the lengthy migration, "but do I think it's a very rare occurrence."