IBA Major Brown Rock
Rivers Inlet, British Columbia
Site Summary
BC253 Latitude
51.425° N
127.700° W
0 - 10 m
12.85 km²
open sea, inlets/coastal features (marine), coastal cliffs/rocky shores (marine)
Land Use:
Not Utilized (Natural Area)
Potential or ongoing Threats:
Oil slicks
IBA Criteria: Nationally Significant: Congregatory Species
Conservation status:
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Site Description
Major Brown Rock lies on the western reaches of a group of islands, within the mouth of Rivers Inlet, on the mainland coast of British Columbia. Much of the islet is a low, bare rock with a sandy beach-like enclave in the interior. The higher northwest side is vegetated with various grasses and forbs (including Elymus, Heracleum, Conioselium and Mimulus) and a pocket of salmonberry and currant shrubs. The surrounding marine area is of importance for foraging birds. Major Brown Rock is about ten kilometres northeast of Dugout Rocks in the Smith Sound Islets IBA.
Major Brown Rock is a site of national significance with 319 pairs (over 1% of the national population) of Glaucous-winged Gulls recorded nesting there during surveys in 1988. Larger numbers of non-breeding gulls roost there as well. Several pairs of nesting Black Oystercatchers breed on the islet, but not in nationally significant numbers. In some years, small numbers of Pelagic Cormorants nest on the rock and it is likely that Pigeon Guillemots nest there as well.

Several species of shorebirds (eg. Western, Least, and Spotted Sandpipers, Surfbirds, and Black Turnstones) occur there in small numbers, with occasional sightings of more than hundred recorded during the infrequent summer surveys. Of note was a flock of 450 Black Turnstones during a survey in 1977. In addition to the shorebirds and gulls, Harlequin Ducks frequent the shoreline areas.

IBA Criteria
SpeciesT | A | I Links Date Season Number G C N
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
As with most coastal sites, oil spills and disturbance from boaters are an ever-present threat. An additional specific threat to this islet was the metal marker buoy structure on the northwest corner of the islet. Many birds became trapped, and subsequently died inside the marker after gaining access through a hole in the top of the structure. The presence of numerous carcasses and skeletons in the bottom of the chamber suggested that this had been going on for some time. During the 1988 colony survey, this hole was plugged with wood as a temporary measure to prevent access. It is not certain how common this site-specific mortality is on other islands with similar markers.

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.
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