Bird ringing in Britain and Ireland in 2007

Abstract

This is the 71st annual report of the British Trust for Ornithology's Ringing Scheme, covering work carried out, and data received, in 2007. In partnership with EURING, a web‐based application was developed to map migration routes of waterfowl species identified as being those with the highest potential to carry Highly Pathogenic Avian Influenza H5N1 across Europe. This application used recovery data held in the EURING database. The 25th year of Constant Effort Site (CES) ringing demonstrated how the heavy rainfall during the summer of 2007 had a largely negative effect on breeding success, with productivity of ten species significantly lower than the long‐term average, although that of four species was significantly higher. These contrasting fortunes are likely to be related to the timing of the heaviest rains in relation to breeding stage. For several species, there were also continued declines in adult abundance and there is particular concern for Sedge Warbler, Reed Bunting, Lesser Whitethroat and Linnet, which reached their lowest‐ever levels since CES monitoring began. Data for 96 Retrapping Adults for Survival (RAS) studies were submitted, covering 34 species, including six Red‐listed species and 14 that are Amber‐listed. The total number of birds ringed (786,070) was 7% lower than the mean of the previous five years. This reduction may have been influenced by the heavy rainfall in 2007, which affected breeding success of some species and may have led to fewer opportunities for ringing activities. The recovery total (13,156) was higher than the mean of the preceding five years and the number of recoveries of foreign‐ringed birds (1,368) was the highest annual total ever reported. Recoveries of 223 individual birds are presented in the report. They include unexpected movements, movements that confirm suspected or known migration patterns, and longevity records.