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Bird Islands (NS001)

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Bird Islands (NS001)

Cape Dauphin, Cape Breton Island, Nova Scotia

Latitude 46.376°N
Longitude 60.384°W
Altitude 0 - 20m
Area 10.89km²

Site Description

The Bird Islands are located in northeastern Cape Breton Island, approximately 4 km off Cape Dauphin. They consist of two long, narrow islands that are oriented in a northeast/southwest straight line. Hertford Island, located closest to shore, is approximately 1.1 km long and about 120 m wide. Ciboux Island, which is located directly northeast of Hertford Island, is slightly larger, being approximately 1.6 km long and about 120 m wide. Steep twenty-metre high cliffs, with numerous holes and ledges, ring the perimeters of both islands. The vegetation consists of stunted shrubs along with areas of grass and other forbs. These grassy tops were formerly grazed by herds of sheep. Numerous reefs and rock clusters are located between the two islands.

Birds

The Bird Islands support the largest colony of Great Cormorants in North America. A three-year average, using the 3 most recent years that the area was surveyed, was 565 nesting pairs. These do not reflect exact numbers, since the individual birds move frequently when surveys are being conducted. If approximately accurate, this number represents as much as 9% of the western Atlantic (North American) population.

Although Great Cormorants often breed inland in Europe and Asia, they are strictly coastal breeders in North America. Cormorants prefer nest sites that are within commuting range of adequate food resources and safe from terrestrial predators. As a result, isolated islands, and steep rocky cliffs that are within commuting range of adequate food resources, are favoured as nesting sites.

In addition to Great Cormorants, several other seabirds nest on the cliffs the Bird Islands are the largest concentration of Black-legged Kittiwakes, Razorbills and Atlantic Puffins within Nova Scotia. Numbers of the first two species have increased since the 1980s, with an average of 960 kittiwake, 150 Razorbill, and 75 puffin nesting pairs over the last five surveyed years (between 1990-1997). A few hundred nesting pairs of Double-crested Cormorants, over 300 Black Guillemots, and Leachs Storm-Petrels also breed on here.

Other birds that have been observed on the islands include: Spotted Sandpipers, yellowlegs, Cliff Swallows, Herring Gulls, Greater Black-backed Gulls and Starlings.

Conservation Issues

Hertford Island is a Nova Scotia Bird Society Sanctuary, while Ciboux Island is not currently protected. There are concerns about potential oil pollution and human disturbance. Occasionally people in small boats land on the island and cause unnecessary disturbance to the nesting birds. This area was recognized as important by the International Biological Programme, of the late 1960s and early 1970s.

IBA Criteria Habitats Land Uses Potential or Ongoing Threats Conservation Status
Great Cormorant
Number Year Season
3002001Summer
5001999Summer
2501997Fall
8301997Summer
1,4741993Summer
1,0861991Summer
1,0821988Summer
1,7721984Summer
8461982Summer
1,8081981Summer
1,0221980Summer
9681979Summer
Black-headed Gull
Number Year Season
102009Fall
Razorbill
Number Year Season
1,2002017Summer
1,0002016Summer
1,8002013Summer
7001999Summer
4301997Summer
2781995Summer
3721993Summer
1641991Summer
2621990Summer
1661989Summer
1761988Summer
1221984Summer
1101982Summer
2021981Summer
1381980Summer
1381979Summer