September 25th, 2017
Sable Island was surveyed for terns in June 2006 using ground-based surveys by the Canadian Wildlife Service. The island was crossed every kilometre from north to south. Tern colonies were identified and subsequently surveyed. 2426-3960 pairs of terns were identified at 13 colonies. Even accounting for the uncertainty in the estimate, the total suggests that the breeding population has increased considerably over the last five years, mainly because of the growth in a colony near the main station. Species composition of breeding birds at surveyed colonies was 74% Common Terns and 26% Arctic Terns. Three Roseate Terns were identified but breeding status was not confirmed. The average clutch size was 2.41(±0.65) which is comparable to other surveys of terns in the Maritimes (A.W. Boyne pers. obs.).