Black-headed Gull Chroicocephalus ridibundus

(last update: 19-03-2014)

Black-headed Gull - 1cy December

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 December

In December, first-calendar year Black-headed Gulls are in full "first winter" or "formative" plumage. This plumage is characterized as follows:

• The mantle and scapular feathers are gray (as adult), while some brown, juvenile feathers can be retained
• The head is 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 (as adult)
• Faintly gray shine extending from the mantle to the lower neck and sides of the breast
• The body is white
• The bill is orange with a black tip
• The legs are orange
• Moult has not taken place in the wing and tail feathers and therefore remain first-generation. Sometimes though, some lesser and medium coverts are moulted to second-generation, gray feathers (as adult)

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.

Observation of 1cy birds in December reveal that a substantial number of birds are still in active moult, replacing the wing coverts and lower scapulars. Therefore, it seems to be likely that the partial autumn moult in 1cy birds may continue into the next spring moult in 2cy. Exact data are not presented here, but in several images of 1cy December birds on this page, this extensive partial moult can be seen (see here and here).

Black-headed Gulls in December, compared by age group

1st calendar year	2nd calendar year	Adult