The efficacy of the colour‐ringing system used for herring gulls Larus argentatus and lesser black‐backed gulls Larus fuscus in Bristol 1980–1997

Abstract

Details of the colour‐ringing scheme used for nestlings of the Herring and Lesser Black‐backed Gulls which breed on rooftops in Bristol are presented. Mean recovery rates of 61.0% and 55.1% respectively have been achieved, showing that the information return on birds after fledging is significantly higher than that achieved by the use of metal rings alone or by using standard colour and metal ring combinations. High recovery rates and rapid data collection are possible if ringers make the effort to find their colour‐ringed birds. An increase in interest in the large gull species particularly during the last five years amongst non‐ringers has resulted in an increase in reporting rates. Repeat sightings of colour‐ringed individuals, too, can be numerous. It is proposed that in terms of results obtained, the system used in Bristol is a most effective tool for in‐depth studies on the large gulls and, possibly, other larger bird species.