McLaren, IA. 1981. The Birds of Sable Island, Nova Scotia. Proceedings of the Nova Scotian Institute of Science, 31, 1-48.

Abstract

A total of 324 species of birds, 236 authenticated by specimens or photographs, are reported from Sable Island, a treeless sandbar 150 km from the nearest mainland of Nova Scotia. Historical records are reviewed, especially the underappreciated collections and observations by James and Richard Bouteillier between 1894 and 1910. Extensive records have been kept since 1963, including quantitative daily lists of birds during 1967-1979. Research on the Ipswich Sparrow, Least Sandpiper, Larus gulls, and shorebird migration, is reviewed briefly.

Twenty-five species nest or have nested on the island. Almost all the species that breed in Nova Scotia, or are normal migrants or eruptives to the province, except for a few mostly sedentary or rare species, have occurred on the island. For the period 1967-1979, extreme and median migration dates, and estimated numbers of occurrences and individuals, are given for all species except seabirds and year-round residents. Landbird migrants, about 6 times more common in autumn than in spring, are not as common as on islands nearer the Nova Scotian mainland, where about 5 times as many have been listed on comparable days.

Eighty-five species defined as migrants in the province have been reported from the island, most based on specimens or photographs, or on well-documented sightings. These include 2 first records for North America, 4 for Canada, and 24 for Nova Scotia. In comparison with other localities in eastern North America, the proportion of landbird vagrants from more remote ranges is higher on Sable Island.

The island has also produced many late and early provincial records of migrants, including some totally unseasonable ones. A substantial amount of summer wandering by presumed nonbreeders is evident. A number of boreal and arctic-subarctic species have occurred during summer. Winter appearances by “half-hardy” species imply a sustained capacity for migratory escape from deteriorating conditions.

Extensive records from the late 19th and 20th centuries allow assessment of historical changes. Herons, terns, and shorebirds have changed in abundance over their wider ranges. Wintering waterfowl and some breeding species have declined because of the virtual disappearance of Wallace Lake, a once-extensive lagoon. Populations of some of the most abundant vagrants today, not reported in earlier years, may have responded to proliferating second-growth habitats.