Black-headed Gull Chroicocephalus ridibundus

(last update: 19-03-2014)

Plumages

Migration

Black-headed Gull - Adult January

This section deals with adult Black-headed Gulls in the month of January.

Introduction

Partial moult into summer plumage (head and body) usually takes place December to April, but majority January to March. Moult starts with surrounding dark head-stripes. Hindneck generally first, forehead and chin latest. From June on, hood becomes gradually paler and duller.

Adult summer plumage is characterized as follows:

• Head: Hood rather small and elliptical shape, not extending to nape. Colouration is dark chocolate-brown, rear margin darkest. White crescents above and below eye, usually  joining at rear. Orbital ring maroon- red. Iris brown. Bill dark maroon- red. Mouth and gape btright red. Hindneck white.
• Upperparts and most of wing coverts: mid grey. Marginal coverts and outer primaries coverts: white.
• Upperwing ‘tricoloured’: grey, with a white triangle on the outer primaries (P7-P10) and a black wing-tip pattern on p5-p10.
• p7-p10: white (P10 with black edge of outer web not reaching tip)
• p5-p10: black-tipped, extending on to inner edge of inner web
• p1-p6: grey with blackish-grey innerwebs on p1-p5
• secondaries: grey with white tips
• Underwing: outer primaries white, dark tipped, mid primaries dark
• Axillaries and lesser underwingcoverts: greyish-white
• Legs dark reddish.  
• Tail: all white

Most of the description follows: 
P.J. Grant: "Gulls, a guide to identification".
K.M.Olsen: “Gulls of Europe, Asia and North America”.