IBA The Brothers
Lower West Pubnico, Nova Scotia
Site Summary
NS003 Latitude
43.633° N
65.825° W
0 - 3 m
4.51 km²
mud or sand flats (saline), coastal sand dunes & beaches, open sea, inlets/coastal features (marine)
Land Use:
Nature conservation and research, Fisheries/aquaculture, Hunting
Potential or ongoing Threats:
Disturbance, Urban/industrial development
IBA Criteria: Globally Significant: Congregatory Species, Nationally Significant: Threatened Species
Conservation status: IBA Conservation Plan written/being written
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Site Description
The Brothers are two islets located about 700m from the southwest (Gulf of Maine) coast of Nova Scotia. The hamlet of Lower West Pubnico is located on the mainland about 1 km from the adjacent coast. The islets are low and partially covered with grass and herbaceous plants. The Brothers and the mainland coast have 'beach rock' shores - that is beaches composed of weathered and rounded stones made of hard, often granitic material. The climate is maritime, with much fog and mild winters. The tides range from 4 - 5 m.
ince thorough tern surveys were initiated in the 1980s, The Brothers have consistently supported one of Canadas largest Roseate Tern populations (Roseate Terns have been designated as nationally Threatened by COSEWIC). When the colony was first identified in 1982, it contained 55 to 60 pairs. Numbers declined to a low of 20 pairs in 1991, but have subsequently experienced a steady increase since local residents began active conservation efforts. In recent years, the number of breeding pairs has once again ranged between about 50 and 60 (1996 48 pairs; 1997 54 pairs; 1998 - 59 pairs; 1999 61 pairs).

Roseate Terns on The Brothers represent about half of the estimated Canadian population. The Brothers are also of international significance in that the 50 to 60 pairs or Roseate Terns recorded over the last few years represent about 1.5% of the estimated North American Roseate Tern population. (Based on surveys completed in 1996 and 1997, the Canadian Roseate Tern population has been estimated to lie somewhere between 87 and 137 pairs. In 1997, the U.S. Roseate Tern breeding population was estimated at 3,382 pairs).

In addition to Roseate Terns, Arctic and Common Terns also nest here in numbers ranging from 300 to 500 pairs. Terns (unspecified) have nested here for at least 60 years; the Roseates began to attract attention when the species was suggested as threatened in the early 1980s. Local interest in the population was increased through the Maritimes Atlas project (1986-1990).

IBA Criteria
SpeciesT | A | I Links Date Season Number G C N
Black-headed Gull 2013 WI 5
Roseate Tern 2015 - 2016 SP 2 - 9
Roseate Tern 1991 - 2017 SU 2 - 172
Roseate Tern 1994 WI 68
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 Brothers tern colony has been monitored since 1982, and inventoried annually since 1991. Since 1990, there has been a strong local effort to attract and encourage nesting terns. The colony is visited regularly throughout the breeding season and all gull nests are removed. Since 1991, tern nesting boxes have been installed and maintained (Roseate Terns generally prefer more nesting cover than Common or Arctic Terns). The nest boxes consist of a three-sided, five inch high box that is turned upside down, and weighted with rocks. The success of these efforts has been demonstrated by the increasing Roseate Tern population at this site, although intensive American Crow predation resulted in the survival of only 1 or 2 Roseate Tern chicks.

In 1994, an aquaculture facility was established adjacent to North Brother Islands. There was concern that the aquaculture operation would disturb the tern colony and result in reduced productivity or possibly abandonment. Fortunately, these concerns were not realized. The Brothers have been owned by the Province of Nova Scotia since 1990 and may eventually be designated as a Provincial Wildlife Management Area.

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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