IJZENDOORN AJLV (1951) Three recent cases of melanism in the Black-headed Gull (Larus ridibundus). LIMOSA 24 (1): 53-55.

On 29 January 1944 I was bicycling along the coast of the IJsselmeer (the former Zuiderzee) some 4 kilometers S. of Hoarn, Holland, near the village of Scharwoude, when my attention was drawn to a peculiar bird, with a color~arrangement never seen by me before..
      The bird was walking in a wet, low~lying meadow and it did not have any companions. I could approach the bird to about a 10 meters' distance and soon found out that it could only be a me1anistically colored B1ackheaded Gull (Larus ridibundus (L.)). I could study the details of its plumage for over a quarter of an hour with the aid of 8~times magnifying binoculars. The gull was on the whole very dark brown and some parts of the plumage were even close to black. The underparts showed an intensification of color from chin to tail: chin and throat being rather dark greyish, while this color was changed to a dull brownish black on the belly, the breast being of an intermediate shade of brown. The crown and nape were blue-grey, intermixed with darker, brownish streaks; the sides of neck and head were dirty-white, with the2haracteristic dark-brownish patch on the hinder ear-coverts. The color of the underwing 'was again very dark, nearly black, with a brown hue. The upper wing-feathers had a lead-'grey color, but were very much darker than in normal Black-headed Gulls, which were present for comparison on the same meadow, together with approximately 1000 Common Gulls (Lams canus L.). The white margins to the front of the wings, nearly from the carpal joint to the wing-tips, so typical of a Black-headed Gull's wing-pattern, were very conspicuous. There was a black edge, hardly visible, on the hinder border of the wing. Near the carpal joint there was a dark-brown patch on the upper wing-coverts. The feathers of the back were dark greyish. The upper tail coverts were again extremely dark. they seemed to be nearly sooty black. The tail, however, was contrastingly pure white. The legs proved to be very dark red and so was the bill, which had a black tip. The color of the irides was not observed. Posture, build, behavior, and some of the characteristics mentioned above proved the bird to be an aberrantly colored Black-headed Gull. Chroicocephalus ridibundus = Larus ridibundus

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