Black-headed Gull Chroicocephalus ridibundus

(last update: 19-03-2014)

Black-headed Gull - 1cy June

Introduction

The Black-headed Gull is a small gull, common and widespread in Europe and Asia all the way to the east through the Russian steppe-belt into Kamtchatka. It winters south along the west coast of Africa, the Mediterranean and the east coast of Africa, the Arabian peninsular, India, Malaysia and the Philippines. A key characteristic is the white on the outer primaries which is very distinctive in flight, even from a great distance.
The Black-headed Gull reaches the adult plumage in second winter: 3cy (third-calendar year) birds are hardly distinguishable from adults.

Most of the description on these pages follows from P.J. Grant: "Gulls, a guide to identification".

1cy Black-headed Gull in June

Downy young are dark buff-coloured and heavily marked with dark patches on the head and upper body. The underbody is unmarked. The bill is dark pink to black, the legs dark pink.

Within a few weeks, the juvenile plumage will be acquired. In this mainly orange-brown plumage, the darkest individuals especially cannot be confused with any other species. The head marking is predominantly as that of winter (basic) plumage (dark ear spot, connected by a faint band across the crown), but can also extend to a dark crown or partial hood. The breast, flanks, mantle, tertials and wing coverts are yellow-brown; the chin, throat and collar is markedly white. The light edges of the yellow-brown feathers result in a scaled effect. The bill is dull flesh with a black tip, the legs are (dull) flesh. The iris and orbital ring are dark brown.

In flight, the dark carpal bar on the upper wing stands out, formed by the lesser- and medium coverts. The trailing edge is black, similar to the tail edge (the outer tail feathers of some individuals are completely white). The primaries have a white base, extending in a drop-shape to a black tip. The outer primaries usually have small white tips and can have a large amount of black in the outer web, thickest on the mid-part.

Immediately after a Black-headed Gull abandons its nest, the post-juvenile moult begins (moult into "first winter" or "formative" plumage). This phase starts with the mantle and scapular feathers and is normally completed by September. During this moult, the following parts are replaced:

• Mantle and scapular feathers are replaced by gray feathers (as adult), some juvenile feathers are retained
• The head turns white with a black ear spot, combined with a faint band across the crown, as well as a faint band from eye to eye across the top of the head
• Faintly gray shine extending from the mantle to the lower neck and sides of the breast
• The body turns white
• The bill and legs turn (yellow-)orange by the autumn
• The wing and tail feathers are not replaced and therefore remain first-generation; sometimes though, some lesser and medium coverts are moulted to second-generation, gray feathers (as adult)