Dorchester Cape is a rocky cape that extends into the bay, and Grand Anse is an area of sand and gravel beaches situated along the eastern coast of Shepody Bay, in eastern New Brunswick. It is adjoined by a large ledge of intertidal mud flats, known as Bucks Flats. Grand Anse is within the town of Johnsons Mills. One of the characteristic features of the shorelines of the Bay of Fundy, such as this, are the macro-tides ranging from 10 15 m, the highest in the world. Low tide exposes vast mud flats at this site, which extend at least 2 km seaward, providing a huge open area for shorebirds to forage for abundant invertebrates. The land adjacent to the flats is poor and infertile and thus does not support agriculture.
The Dorchester Cape and Grand Anse areas are vitally important for roosting and feeding migrant shorebirds. The Semipalmated Sandpiper is by far the most abundant shorebird in the Bay of Fundy during fall migration, with up to 200,000 birds recorded at the roost site during peak migration. This figure accounts for about 5.6% of the world population and is a recent recalculation of estimates made between 1975 to 1983. More recent estimates (1995) show that a similar number of birds continue to use the area today. About 50 and 95% of the worlds population of Semipalmated Sandpipers use this and other IBA sites in the Bay of Fundy at peak of migration in early August.
Dorchester Cape is also extremely important for migrating Dunlin. An estimated 2,027 Dunlin use this part of Shepody Bay, representing almost 1% of the central Canadian breeding population. Significant numbers of Semipalmated Plovers (678) have also been observed, which is more than 1% of their global population. Black-bellied Plovers are one of the only shorebirds that are found at the Bay of Fundy in equally large concentrations during both spring and fall migration, with a maximum count of 807 in the fall of 1994.
Numerous other shorebird species are found at Dorchester Cape, including Short-billed Dowitchers, Least Sandpipers, Red Knots, and White-rumped Sandpipers (in some of the highest numbers in the region, 227 birds). Shorebird flocks move back and forth between Dorchester Cape and Marys Point (Shepody Bay West) to varying degrees depending on the tidal cycle, and thus the highest counts at both sites most likely involve some duplication.
BirdLife International (2021) Important Bird Areas factsheet: Dorchester Cape and Grand Anse. Downloaded from http://www.birdlife.org on 24/06/2021.