The Fair Isle Wren: population and territory occupancy, 1950-2010

摘要

The Fair Isle Wren Troglodytes troglodytes fhdariensis is a subspecies restricted entirely to the small island of Fair Isle, in Shetland. It is the least numerous subspecies of bird in Britain and perhaps Europe. In the 1950s and 1960s, the populationfluctuated around a mean of 39.6 territories, with a peak of 52 in 1964.The population was at its lowest ebb in the late 1970s and early 1980s, with just ten singing males in 1981, but since 1987 the population has varied around a mean of 30.6 territories. Population levels and territory occupancy since 1950 are discussed in this paper, which speculates on some of the factors that affect the trends and patterns observed.