Bird ringing in Britain and Ireland in 1996

Abstract

This is the 60th annual report of the British Trust for Ornithology's Ringing Scheme, presenting the data received in 1996. The development and implementation of a Scientific Strategy for the Ringing Scheme is discussed, together with examples of future work and data analysis. The strategy provides a coherent approach to the collection of data needed for future analytical work on bird populations within Britain and Ireland, ensuring that questions of conservation importance are addressed. The number of birds ringed during the current period (851,237) was slightly down on that for 1995, but remained some 2.8% up on the mean for the previous five years. For several species there were changes in the number of individuals ringed (when compared with previous years) which could not be explained by changes in ringing effort. These included increases for Firecrest, Fieldfare and Barn Owl and a decrease for Crossbill. The total number of recoveries for the period (12,342) is nearly 5% down on the mean for the previous five years. Standardised ringing at 122 Constant Effort Sites revealed a poor breeding season for the majority of the 27 core species covered. Early breeders were particularly affected by poor weather in May and a scarcity of invertebrate food in April.