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Northern Harrier flying
Northern Harrier © Kyle Wilmarth

Important Bird Area: Mt. Greylock

Map of the Mt. Greylock IBA site

Nominated By

René Laubach


12,496 acres

Towns and Counties

Adams, Cheshire, Lanesboro, New Ashford, North Adams, Williamstown; Berkshire


Department of Conservation and Recreation

Major Habitats

30% spruce-fir forest, 60% northern hardwood forest, 5% early successional shrubland, 2% cultural grassland, 1% powerline, 1% lake/pond

Land Use

15% nature & wildlife conservation/land trust, 24% hunting/fishing, 10% other recreation or tourism, 2% forestry, 50% water supply, 1% right-of-way

Serious Threats

recreational development and overuse

Minor Threats

non-native invasive plants, ecological succession, water and air pollution

IBA Criteria

  • Category 1: Sites containing assemblages of species characteristic of a representative, rare, threatened, or unique habitat within the state or region.
  • Category 2: Sites regularly holding significant numbers of species of high conservation priority in Massachusetts.
  • Category 4: Sites regularly holding significant numbers of an endangered, threatened, vulnerable, or declining species.

Site Description

Mount Greylock is the state's highest peak at 3,491 feet. The upper 800 to 900 feet of elevation sets Mount Greylock apart from any other place in the Commonwealth. This was the first state reservation in Massachusetts, established 1898. The peak's upper section is host to a boreal plant community not found elsewhere in the state. Characterized by balsam fir and red spruce, this zone is reminiscent of the vast boreal forest of Canada. Mount Greylock is also one of the state's largest reservations. It contains some 68 miles of hiking trails, including 13 miles of the Appalachian National Scenic Trail. Bascom Lodge, constructed on the summit by the Civilian Conservation Corps from 1933 to 1937, provides lodging to numerous Appalachian Trail through hikers and caters to thousands of day visitors each year. A 1,600-acre area within the Hopper, a glacial cirque on the peak's western side, was designated a National Natural Landmark; it contains stands of 200-year-old Red Spruce (including the state's largest) and old-growth Eastern Hemlock. The boreal zone (especially 3,000 feet and above) contains what may be the state's only breeding Blackpoll Warbler. Swainson's Thrushes also nest in the damp coniferous forest, as do White-throated Sparrows and Dark-eyed Juncoes. Mourning Warblers still nest in cutover, regenerating areas. The Yellow-bellied Flycatcher is a strongly suspected nester, and the Olive-sided Flycatcher nested regularly in an area that has now grown up to tall spruces. Historically, a small population of Bicknell's Thrushes nested near the summit. Though the Bicknell's has been absent as a breeding species since 1972, one individual was heard vocalizing on the peak during the summer of 2000.

Current Conservation Status

This IBA's state owned and protected. Over the last six decades several proposals have been put forth to open the summit to various forms of development; among these were a tramway and ski resort proposal in the 1960s, a casino proposal, and, most recently, a state plan to develop an adjoining 1,000-acre parcel on the eastern lower slope of the mountain known as Greylock Glen. Each time citizens have defeated these development proposals. The ultimate fate of the Greylock Glen proposal is still in question. Mount Greylock State Reservation is a unique resource for all of the citizens of the Commonwealth as well as for tourists and represents the crown jewel of the state's park system. The reservation and the wildlife it supports deserve the highest level of protection possible.

Ornithological Significance

Special Concern Species: The boreal forest zone of Mount Greylock holds the state's entire population of the Blackpoll Warbler. Mourning Warblers breed in early successional habitat on the mountain's slopes. Other high conservation priority species represented by at least 25 breeding pairs include the Hairy Woodpecker, Eastern Wood-Pewee, Least Flycatcher, Great Crested Flycatcher, Veery, Chestnut-sided Warbler, Black-throated Blue Warbler, Black-throated Green Warbler, Blackburnian Warbler, Black-and-white Warbler, American Redstart, White-throated Sparrow, and Rose-breasted Grosbeak. Additionally, the following (with more than 1 percent of their entire breeding population within Massachusetts and at least 25 breeding pairs) nest on the reservation: Wood Thrush, Gray Catbird, Scarlet Tanager. Rare, unique, or representative habitat: Mount Greylock State Reservation contains all the state's lands above 3,000 feet and, by extension, a significant portion of its boreal habitat. It also contains the largest tract of old-growth forest remaining in the Commonwealth.

Louisiana Waterthrush, Canada Warbler, Wood Thrush, Veery, White-throated Sparrow, Purple Finch, Scarlet Tanager, Rose-breasted Grosbeak - B, 28 recorded June 1952 (Veit, Petersen, Breeding Bird Survey, Neumuth)

Other Flora or Fauna of Significance

The summit area, contains boreal species of plants such as Northern Mountain Ash, Bartram's Shadbush, and large-leaved Goldenrod, all at or near the southern limit of their range. Boreal forest in a natural state extends along the ridge of Saddle Ball Mountain part of the Greylock Range where it is accessible via the Appalachian Trail. Stunted Balsam Firs and Yellow Birches grow in the boggy, sphagnum moss-covered soil. Lower mountain slopes are encircled by a band of soils that have a limestone origin and are thus basic. Here rare plants such as Large-flowered Bellwort, Ginseng, and Massachusetts' only Braun's Holly-fern thrive (Weatherbee 1984). Resident mammals include the Black Bear, Bobcat, Fisher, Snowshoe Hare, and Red-backed Vole. Spring Salamanders thrive in the mountain's highly oxygenated streams; for example, at Deer Hill Falls. Spotted and Jefferson/Blue-spotted Complex Salamanders utilize reservation vernal pools for breeding. The Appalachian Brook Crayfish is found in some of the reservation's streams. After nearly a 100-year absence, the Early Hairstreak butterfly was rediscovered on Greylock, (and thus in the state), in 1989.

Data Sources

Brewster, William. 1884. Notes on the Summer Birds of Berkshire County, Massachusetts. The Auk 1: pp. 5-16.

Faxon, Walter. 1889. On the Summer Birds of Berkshire County, Massachusetts. The Auk 4: 39-46, 99-107.

Hendricks, Bartlett. 1999. Berkshire Birds. 3rd Ed. The Berkshire Museum. 75 pp.

Ed Neumuth, USFWS Breeding Bird Survey results.

Rancatti, Ronald E. 1999. Boreal Birds in Northern Berkshire County and Western Franklin County. Bird Observer 27 (6): 304-312.

Veit, Richard R., and Wayne R. Petersen. 1993. Birds of Massachusetts. Massachusetts Audubon Society. 514 pp.

Weatherbee, Pamela. 1984. Mount Greylock. Bird Observer 12 (2):65-78