Featured Rare Bird of the CT River: American Oystercatcher
American Oystercatcher Fun Facts
Length: 17-21 in. long (of which bill is 2 ₃⁄₄ – 4 in.)
Wingspread: about 30-36 in.
Favorite Food: Shellfish (oysters, clams, other bivalves)
Nest: simply a slight mound of sand on the ground dry, flat beaches above the high tide line, often in association with Piping Plovers
Eggs: usually 2-3, laid between late May and early August; incubated for 27 days
Range: Atlantic coast population ranges from Massachusetts south through the West Indies; Also the Gulf Coast of US and Mexico and the Pacific Coast of Baja California
The American Oystercatcher (Haematopus palliatus) is the sole representative of the shorebird family Haematopodidae that occurs in CT. Populations of this species are listed as threatened under the State of Connecticut Endangered Species Act (CTDEEP, 2015).
American Oystercatchers breed in sparsely vegetated open sand, gravel, or cobble beaches (Degraaf and Yamasaki, 2001). This breeding resident of Connecticut suffered severe population losses due to the market for hunted shorebirds. Although protections were established against hunting in the early twentieth century, populations have been very slow to return to Connecticut. The first Breeding Bird Atlas efforts of the late 1980s (Bevier, ed. 1990) produced only five confirmed nesting locations in the state, with none reported from the Connecticut River estuary. Species designated as threatened in the Connecticut Endangered Species Act are known from only nine breeding occurrences in the state.
American Oystercatchers arrive in Connecticut in early to mid-March (Haniseck, 2005) after spending the winter somewhere south of North Carolina (Terres, 1980). By mid-April the females lay two-three eggs on a flat, open beach above the high tide line, usually on a mound of sand from which they can watch for approaching predators. Both sexes take turns incubating the eggs.
Wildlife technicians from the CTDEEP typically erect symbolic string fencing along the high-tide line to remind people walking the beach to remain below the high tide line so as not to step on eggs, or young. The adults, eggs, and chicks have effective protective coloration, which provides excellent camouflage amongst the sand, shell hash, and wrack line of the beach. The chicks are mobile and able to leave the nest site two days after hatching and become capable of flight after about 35 days. By mid-November, most birds have migrated south but a few may remain in CT throughout the winter on rare occasions.
Major threats to the breeding success of this species in CT are similar to those of the Piping Plovers, and Least Terns (see Blog Post for those species). They include predators such as foxes, raccoons, opossums, skunks, feral and free-roaming cats, free-roaming dogs, predatory and scavenging birds, and humans. Extreme heat or cold stress may impact nesting success as well. Connecticut beaches tend to be narrow in cross sectional profile and thus beach-nesting birds such as American Oystercatchers, Least Terns and Piping Plovers may be exposed to intense human pressure proximal to their nesting sites above the high tide line. Once again, we remind you that where you see signs informing the public of beach-nesting birds such as the American Oystercatcher, Piping Plover, and the Least Tern, please respect the warnings to stay out of roped-offed areas demarcating their nesting territories, and do not bring your dogs to beaches with nesting colonies of these rare species. Again, if we respect their space, and continue to “share the shore” responsibly, we will be able to avoid the beach closures at sites supporting nesting pairs of this state threatened species.
One can find more information on Connecticut’s rare species at the following link:
Information on the Connecticut Breeding Bird Atlas can be found here: http://www.ctbirdatlas.org/
CTDEP/CTDEEP, 2015. Connecticut’s Endangered, Threatened and Special Concern Species. State of Connecticut Department of Environmental Protection, 2015: http://www.ct.gov/dep/cwp/view.asp?a=2702&q=323488&depNav_GID=1628
DeGraaf, R. M., & Yamasaki, M. (2001). New England Wildlife: Habitat, Natural History, and Distribution. Hanover, New Hampshire: University Press of New England.
Haniseck, Greg. 2005. Connecticut Birds by the Season. The Connecticut Warbler. A Journal of Connecticut Ornithology. 25 (1) 1-44. January 2005.
Terres, John K. (1980). The Audubon Encyclopedia of North American Birds, Alfred A. Knopf, NY. 1109 pp.
Contributed by Anthony Zemba and Amanda Kenyon. Header photo by Anthony Zemba.