IBA Witless Bay Islands
Mobile, Newfoundland
Site Summary
NF002 Latitude
47.223° N
52.792° W
0 - 86 m
62.08 km²
coniferous forest (boreal/alpine), sedge/grass meadows, coastal cliffs/rocky shores (marine), rocky flats & barrens
Land Use:
Nature conservation and research, Tourism/recreation
Potential or ongoing Threats:
Disturbance, Fisheries, Other increased mortality, Oil slicks
IBA Criteria: Globally Significant: Congregatory Species, Colonial Waterbirds/Seabird Concentrations
Conservation status: Ecological Reserve (provincial), IBA Conservation Plan written/being written
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Site Description
The Witless Bay Islands are located 4 km off the east coast of the Avalon Peninsula, approximately 35 km south of St. John's, Newfoundland. The site consists of four small islands: Green, Great, Gull, and Pee Pee. All are rocky, with low cliffs and steep, grassy slopes. The two larger islands, Great and Gull, also support coniferous forest communities.
The Witless Bay Islands support a globally significant colony of breeding seabirds. Great Island, in particular supports the largest colony of Atlantic Puffins in eastern North America. A breeding population of more than 216,000 breeding pairs (some on Gull island as well) was estimated in 1994. This represents approximately 3.6% of the global population and possibly as much as 57% of the eastern North America population.

Also present on the Witless Bay Islands are impressive numbers of Leach's Storm-Petrels, Common Murres, Black-legged Kittiwakes and Herring Gulls. Nearly 780,000 pairs of Leach's Storm Petrels have been recorded in the area (the majority breeding on Great and Gull Islands). This estimate represents approximately 9.5% of the global and 16% of the western Atlantic population. Approximately 77,500 pairs of Common Murres have also been reported (almost 2% of the Atlantic and over 13% of the eastern North American breeding population). Black-legged Kittiwakes also breed on the islands. Approximately 43,500 pairs have been estimated, which represents as much as 16 to 22% of the western Atlantic breeding population. Approximately 7,000 pairs of Herring Gulls (approximately 5% of the eastern North America population) have also been recorded. Other species of seabirds nesting on these islands include Great Black-backed Gulls, Black Guillemots, Thick-billed Murres, Razorbills, and Northern Fulmars. The marine areas surrounding the islands are also important for migrating sea ducks such as White-winged and Surf Scoter, Oldsquaws, and Common Eiders.

IBA Criteria
SpeciesT | A | I Links Date Season Number G C N
Atlantic Puffin 2000 - 2017 FA 8,000 - 100,000
Atlantic Puffin 2010 - 2017 SP 10,000 - 100,000
Atlantic Puffin 1994 - 2017 SU 9,000 - 500,000
Black-headed Gull 2012 SU 20
Black-legged Kittiwake 2013 FA 50,000
Black-legged Kittiwake 1985 - 2014 SU 25,000 - 87,000
Common Murre 2014 FA 100,000
Common Murre 1985 OT 155,000
Common Murre 2017 SP 250,000
Common Murre 2009 - 2016 SU 50,000 - 800,000
Herring Gull 2011 - 2013 FA 5,000 - 10,000
Herring Gull 1994 SU 13,990
Leach's Storm-Petrel 1994 SU 1,560,000
Razorbill 2010 - 2014 SU 750 - 500,000
Note: species shown in bold indicate that the maximum number exceeds at least one of the IBA thresholds (sub-regional, regional or global). The site may still not qualify for that level of IBA if the maximum number reflects an exceptional or historical occurrence.
Conservation Issues
The Witless Bay Seabird Sanctuary Ecological Reserve, which includes Gull, Green, and Great Islands, was established in December, 1983 under the Wilderness and Ecological Reserves Act. As a result, the islands are shielded from most direct threats. There is however, increasing concern about the levels of ecotourism. During the peak of the season, as many as 10 to 15 tour boats per day visit the area. The auks, in particular, appear to be sensitive to the disturbance.

The colony is a base for a series of long-term ecological studies of seabirds, sponsored by the Canadian Wildlife Service and Memorial University of Newfoundland.

The IBA Program is an international conservation initiative coordinated by BirdLife International. The Canadian co-partners for the IBA Program are Birds Canada and Nature Canada.
   © Birds Canada