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Roseate Tern

Mahone Bay Roseate Tern Recovery

Project Summary

Bluenose Coastal Action Foundation initiated the Roseate Tern Recovery Project (RTRP) in April 2003. The primary goal of this project was to re-establish a secure nesting site for endangered Roseate terns on an island in Mahone Bay, Nova Scotia. This goal would fulfill the third objective of the “Recovery Strategy for the Roseate Tern in Canada”, which hopes to restore a broader distribution of Roseate terns by establishing at least one more managed colony. Historically, one-third of the Canadian Roseate tern population nested on Grassy Island in Mahone Bay. In the mid 1990’s, this population sharply declined until there were no known nesting pairs. Currently, less than 100 pairs of Roseate terns nest in Canada on three established colonies (North Brother Island, Country Island, and Sable Island).

During the first year of the project, Coastal Action determined the most appropriate stewardship site for Roseate terns in Mahone Bay; Quaker Island was chosen. From 2004 to 2007, Coastal Action facilitated research on the island to establish a Roseate tern colony by using tern decoys, sound systems, nesting boxes, predator deterrence, and predator control measures. Unfortunately, successful stewardship on Quaker Island was not accomplished due to mink predation, severe storm events, and potentially anthropogenic disturbances. The lack of tern breeding success on Quaker Island led Coastal Action to refocus their efforts in 2008 and 2009. During these field seasons, Coastal Action conducted bay-wide surveys at a maximum of three times per week to document tern distribution, abundance, productivity, and reproductive success. Based on observations from boat and land, terns attempted to nest on Crow, Gully, and Westhaver Islands in 2009, and were successful on Westhaver Island. Only Common terns were confirmed in the bay; therefore, no Roseate terns nested in Mahone Bay.

For the 2010 field season, the Roseate Tern Recovery Team recommended a tern stewardship program be initiated on Grassy Island for the following reasons: the habitat is suitable for breeding terns and, because of its history; the island may easily attract terns. The island is also located offshore, which limits anthropogenic disturbances, but is close enough to be regularly monitored. Grassy Island is a Management Wildlife Area owned by Nova Scotia Department of Natural Resources. Therefore, all gull deterrence and management efforts would have to be first approved by the department and the Canadian Wildlife Service. During years 2010, 2011  and 2012, tern attractants such as a sound system playing tern calls and tern decoys were placed on Grassy Island. Gull deterrence efforts were used on Grassy and Westhaver Islands. 

Unfortunately, despite efforts on Grassy Island, only one pair of Roseate Terns was observed during one year, in 2011. Due to lack of success attracting terns to Grassy Island, and growing tern colonies elsewhere in the province, the Grassy Island Stewardship project was discontinued following summer 2012.

In addition to monitoring, Coastal Action implements a Public Education and Outreach Program and a Tern Colony Signage Program. Seabird Nesting Signs were posted on any islands with observed tern activity, The outreach program aims to inform users of Mahone Bay’s islands and local groups in Lunenburg County of the presence, conservation status, and recovery actions required for endangered Roseate terns. Coastal Action also informs the public of the RTRP’s work and objectives. The Tern Colony Signage Program was created to enhance public recognition of and respect for tern colony avoidance signs. Ultimately, this would decrease human disturbance on tern colonies, leading to healthier Common and Arctic tern colonies in Mahone Bay. The decrease in human disturbance events in the bay should attract and shelter Roseate terns; allowing reproduction and recovery of this endangered species.