Black-headed Gull Chroicocephalus ridibundus

(last update: 19-03-2014)

Black-headed Gull - Adult May

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

Introduction

Adult Black-headed Gulls in May are in full summer plumage.

This 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”.