Important Bird Areas

Connecticut College Arboretum


This site has two distinct sections, both of which are part of the Connecticut College Arboretum south of Gallows Lane. They are owned and managed by Connecticut College. One section is the Bolleswood Natural Area, a mature hemlock - hardwood forest that is maintained for scientific research. The only active management permitted in this area has been the creation and maintenance of trails and an exterior fence. Although most of the hemlocks at the site are dying because of woolly adelgid infestation, there is still a high canopy of American beech, red maple, and red, white and black oaks. A 50-foot ravine with an intermittent stream bisects the natural area. The second section of this area is a park-like collection of trees and shrubs of eastern North America centered on an artificial pond with marshy edges. It is contiguous with the Bolleswood Natural Area.

Ornithological Summary

The Bolleswood Natural Area is important primarily because it is the site of one of the longest studies of bird populations in the country. Bird populations were censused every 2-4 years between 1953 and 1976, and annually between 1982 and 1997. The censuses will continue every 1-2 years in the future. The data on bird populations is exceptionally valuable because vegetation changes have been monitored intensively since 1952. Analysis of changes in the bird community has contributed to our understanding of successional changes and forest fragmentation. The results have been printed as Breeding Bird Census reports in Audubon Field Notes (1955-1976), American Birds (1983-1988), and Journal of Field Ornithology (1989-1996), and are available on a database maintained at Cornell Laboratory of Ornithology. These results have been described and interpreted in several publications. In addition, several high conservation priority species for Connecticut regularly nest in the Bolleswood Natural Area, including: Broad-winged Hawk, Eastern Wood-Pewee, Great Crested Flycatcher, Eastern Kingbird, Wood Thrush, Black-and-white Warbler, Louisiana Waterthrush, Scarlet Tanager, and Eastern Towhee. The plant collections area is a planted habitat, but is included in this Important Bird Area because it provides a buffer area for the natural area and an important stopover site for migrating songbirds during spring and fall. The shrubby border and woods along the edge of the pond and in the woodland wildflower garden are "hot spots" for warblers, vireos, and other migrating songbirds.

Conservation Issues

The main threat to this site results from habitat fragmentation in the surrounding region. Wooly adelgid threatens the hemlocks on the site, but the nesting species of highest conservation priority are primarily deciduous woodland-nesting species.


Connecticut College


Primary: Deciduous forest. Secondary: Conifer forest, swamp, river/stream,
pond/lake, park (arboretum).

Land Use

Land Use: Primary- Research. Secondary: Nature and wildlife conservation, education.