White-eyed Gull (L. leucophthalmus) & Sooty Gull (L. hemprichii)

(last update: 2-2-2011)

Avi Meir (Israel)
Mars Muusse (the Netherlands)

Sooty Gull L. hemprichii 2CY, March 04 2002, visitor's centre of Nabq National Park, SE Sinai, Egypt.

A typical first winter bird by early spring. The tail feathers are still juvenile, bleached brown with abraded fringes. The pointed primaries are slightly abraded at the tips in this individual. 
The post-juvenile moult from juvenile plumage into first winter plumage may take place between August and March; subsequently, feathers show various stages of wear. Most of the wing-coverts are still juvenile, but a few coverts have been replaced by second generation feathers recently. The post-juvenile moult may still be in progress. First winter birds are often described in publications as "resembling juveniles but with moulted body and head feathers, scapulars and mantle". However, first winter birds including some wing-coverts in this post-juvenile moult might actually be quite common.
Fresh juvenile coverts show broad pale fringes in Sooty Gull, much more obvious than the fringes of juvenile White-eyed Gulls. However, by March these fringes are worn away and the juvenile feathers stand out as plain pale brown very abraded feathers. This individual included some inner greater coverts and randomly some median coverts in the post-juvenile moult. The scapulars and mantle has been moulted in an earlier stage and several feathers already slow slight wear in the fringes and a brown hue.
Note the stronger, straight bill compared to White-eyed Gulls. It has a blue-grey base and a black tip. The ill-defined buffish eye-crescent is much less obvious than similar aged White-eyed Gulls. Note the lack of any blackish feathers on the head and neck, which are typical for White-eyed Gull. The legs are greyish.