Report on bird ringing in Britain and Ireland for 1991

Abstract

This is the 55th annual report of the British Trust for Ornithology's Ringing Scheme. The annual ringing totals (787,320) were lower than any year since 1982, a result of the cold weather in the winter of 1990/91, a poor spring and low breeding populations. Recovery totals (14,107) were, however, the third highest in the last decade. This is a five‐yearly summary report in which annual information is supplemented by summaries of all international recoveries affecting Britain and Ireland. As part of the continued up‐dating of ringing and recovery files revised figures are published for both ringing and recovery totals. Mass‐participation ringing in Senegal, in both spring and autumn, has resulted in 248 controls of BTO‐ringed birds. In addition the first two controls of BTO‐ringed birds were reported by the newly formed Ghanaian scheme. Excellent progress has been made with the Constant Effort Sites scheme with more sites covered than ever before. Staff research effort during the year included investigations on the wader mortality caused on the Wash by the cold of February, survival analysis of Lapwings and further development (and analysis) of mark‐recapture data.