Colour-ringed gulls

To help with ongoing research and to learn more about the movements and behaviours of individual gulls, we need to be able to identify individuals in the field. To allow identification, gulls are marked with a uniquely-numbered British Trust for Ornithology (BTO) metal ring on one leg. The other leg is tagged with a blue colour-ring containing a white unique alphanumeric code that can be read at a distance. The white code on these blue rings start with “W:” followed by three numbers.

Herring gull W: 114. Photo by Drew Baigent

The West Cornwall Ringing Group

The project to identify and monitor “urban” and “rural” gulls was started by volunteers from the West Cornwall Ringing Group in 2013. Every year these trained volunteer bird ringers (as part of the BTO ringing scheme) have been catching and ringing adult herring gulls around towns as well as chicks on roofs and along the coast at more ‘natural’ sites. To date, 582 gulls have been colour-ringed in West Cornwall, of which 467 were ringed as chicks. In 2020, 80 chicks from local wildlife rescue and rehabilitation groups were also colour-ringed before release, allowing us to follow their dispersal and movements as they grow up. This helps us to start answering questions about the ways in which each early-life experiences may shape later behaviour, including whether the “urban” or “rural” environment in which a gull chick hatched influences its later habitat preferences.

Members of the West Cornwall Ringing Group ringing herring gull chicks. Photo by Emma Inzani

The West Cornwall Ringing Group were also involved with the first GPS-tagging of four British herring gulls in St Ives (see Rock et al 2016) and is helping to GPS-tag more herring gulls with Project C-gull. The GPS tags provide us with detailed information on gull behaviour, daily movements and foraging patterns.

Ringing in the gulls’ natural habitat.
Photo by Mark Grantham

To date, we have recorded over 1700 sightings of 262 different colour-ringed gulls ringed by the West Cornwall Ringing Group. Some ringed gulls are seen regularly on local beaches or in urban areas, whilst others wander further afield, with some of our juveniles being sighted in Dorset, London and Normandy.

What do to if you see a colour-ringed gull?

If you see a colour-ringed gull (or even just a metal ring on one leg) and manage to read the code on the ring (taking photos helps), please send your sighting record to If you can tell us What was the number on the ring, and Where and When you saw the gull, we can record this information and share with you any of the gull’s previous sightings.

Ringed herring gull chick. Photo by Emma Inzani

Any information we can collect about the whereabouts of our ringed herring gulls will help us to build a picture of each individual’s life history and how they are faring in this rapidly changing world.

For more information about the West Cornwall Ringing Group, please visit this blog:

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