Pileated woodpecker: Hunted to scarcity in colonial times, the population has tripled, spreading from a remnant concentration in the Berkshires to reach the Boston suburbs.
Beaver: Wiped out entirely in southern New England by 1900 with only small remnant populations in northern Maine, Vermont, and New Hampshire. Now hundreds of thousands live throughout New England, including an estimated 70,000 in Massachusetts.
White-tailed deer: Population reduced to several hundred in Massachusetts by 1900. Now more than 85,000 animals live in the state.
Wild turkey: Reduced to only a few birds surviving in the thickets of southwest Vermont in the 20th century, now tens of thousands populate the region after wild birds were reintroduced from New York and Pennsylvania.
Black bear: Massachusetts population was about 100 in 1970. The number of bears in the state was estimated at 3,000 in 2005 and is growing.
Alewife: Migratory runs of this “foundation” fish — a small species critical as food for larger fish and animals — had nearly collapsed in Maine because of dams on spawning rivers. Spawning runs of some 3 million have been observed on the Kennebec River since a major dam was removed in 1999.
Grey seal: Eradicated from New England waters in the 20th century. A few reappeared in the 1980s around Cape Cod and the islands. A recent aerial survey counted 15,700 of them on the rocks near the Cape and islands.
Cooper’s hawk: Deforestation and hunting caused widescale demise of the population by 1900. They were still rare in the 1970s, but a recent survey found breeding pairs in more than half of the survey grids statewide.
Moose: As populations in northern New England thrived due to forest cutting and limited hunting, moose moved southward into Massachusetts where they’d been absent since the 1700s. Now up to 1,000 moose live in Worcester and Middlesex counties.
SOURCES: State and federal wildlife agencies; Massachusetts Audubon Society; conservation groups