Year of compilation: 2001
About 1% of the population of the dresseri subspecies of Common Eider nests on these islands. Although the numbers of nests have fluctuated over the last 13 years, from as few as 580 in 1995 to as many as 1,658 in 1999, the 12-year average of 857 nests is probably reflective of earlier decades, since in 1966 1,250 were counted. Fluctuations, at least in recent years, have been caused by Red Fox predation – after the high in 1999 the population dropped to 669 in 2000 due to the presence of two foxes.
One researcher estimated that at least 200 Razorbill were present in 1964, while another, possibly underestimating, thought that about 90 birds in total were present in 1966. By 1999 however the colony had increased significantly. In this year 1108 Razorbills, or about 1.5% of the North American Razorbill population, were counted.
Large numbers of Black Guillemots have been recorded nesting along the rocky shorelines. Eight hundred pairs (1% of the North American population) were counted in 1966 and it is assumed that they are still equally as numerous. They are most concentrated on the cliff ledges of Le Gros Pot.
Double-crested Cormorants are the most numerous bird on the islands. In 1999, 1,945 nests were counted; this is equivalent to about 2% of the Atlantic population.
In 1989, roughly 450 Black-crowned Night-Heron nests were counted, representing approximately 8% of the estimated Canadian population. Night-herons have increased in numbers in recent decades at this location, since in the 1960s and early 1970s the number of night-herons was very small.
In addition, hundreds of other birds breed on Îles du Pot à l'Eau-de-Vie. Other breeding species include: Great Blue Heron (57 nests in 1990), Herring Gull (716 pairs in 1999), Great Black-backed Gull (92 pairs in 1999), Common Crow, and Common Raven.
The presence of Red Foxes can seriously effect the number of nesting eiders. Foxes in the St. Lawrence River estuary either swim to islands with colonies of birds or make their way there on drifting ice. Currently (2001), the Société Duvetnor is trying to remove this species from the island. Generally the eiders will not even attempt to nest on an island when a fox is present, but since the female eiders are strongly philopatric, the eider colony is expected to recover once the foxes are either removed or leave the island of their own accord.
Oil spills are a threat to the birds on the islands in the St. Lawrence River and estuary, which is heavily traversed by large ships. During the late spring, tourist boat traffic can become very concentrated around the islands of the estuary, as people are attracted to the large congregations of birds. Such activity can be detrimental to nesting birds.
BirdLife International (2022) Important Bird Areas factsheet: Brandypot Islands. Downloaded from http://www.birdlife.org on 11/08/2022.