Wood duck, mallard, alder flycatcher, swamp sparrow, downy and hairy woodpecker, and the tufted titmouse.

The 19-acre Hatfield Unit of Silvio O. Conte National Wildlife Refuge is located in Hatfield between Cronin Hill Road and Great Pond. The unit includes a portion of the Connecticut River floodplain and a forested upland approximately 150 to 200 feet above the floodplain. There is no developed access point at this time.

The western third of the unit, along Cronin Hill Road, is primarily deciduous forest comprised of white ash (Fraxinus americana), red maple (Acer rubrum), beech (Fagus grandifolia), and black cherry (Prunus serotina) with some white pine (Pinus strobus). There is a steep drop east to the floodplain adjacent to Great Pond. Historically, this pond was part of the Connecticut River mainstem that was cut off, forming an oxbow. Today this wetland complex is listed as Core Habitat and a Priority Wetland and Aquatic Core by the Massachusetts Natural Heritage and Endangered Species Program.