Here are photographs of some of the birds we have caught. They have been taken with different equipment in differing light conditions, so care should be taken in attempting to compare plumage colours. Some images have been edited to remove distracting objects from the rubbish tip in the background, but the birds themselves have not been altered. More photos will be added over time.

Click on the photos in the portrait section to see a gallery of that species.

Click on the links in the ageing guide section to see comparison photos of birds of different ages.

Click on the links in the resightings section to see some of out colour-ringed birds resighted elsewhere.

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Ageing guides

Large gulls are surprisingly variable in plumage, and one of our study aims is to gain a greater understanding of how these variations relate to age and race. Here are reference photos to illustrate the plumage and bare part characteristics that we are using to age the birds we catch.

Herring Gull Larus argentatus

Great Black-backed Gull Larus marinus


As a result of our colour ringing programme, many of the birds we have ringed are now being resighted elsewhere. Several birders have been able to provide photographs of our birds when the rings have been read in the field elsewhere. Most are colour-ring readings, but some birds have had their metal rings read. Members of the North Thames Gull Group group have photographed colour-ringed birds from other schemes, at our sites.

Mediterranean Gull Larus melanocephalus

Lesser Black-backed Gull Larus fuscus

Yellow-legged Gull Larus michahellis

Herring Gull Larus argentatus

Great Black-backed Gull Larus marinus