Vega Gull (vegae) / セグロカモメ / 재갈매기

(last update: December 2015)

Vega Gull (vegae) sub-adult January

Identification and ageing

3rd generation flight feathers in 3rd cycle birds. In general these are adult-like birds, with obvious immature markings. Ageing can be difficult at this age, especially between 3rd cycle and 4th cycle birds. Immature birds with extensive black in the tail and extensive brown wing-covert patches should normally also be in 3rd cycle. However, advanced 3rd cycle and retarded 4th cycle birds are extremely similar, and such birds are probably best labelled "sub-adult".

4th cycle birds are very adult-like, with single vestiges of immaturity, like dark centres on underwing primary coverts, dark centres in some secondaries or some black in the tail feathers. Remember that true adult Vega Gulls hardly develop a full black band on the bill, hence birds that do show a black line on the bill are suspecious and should be checked for any immature characteristics (check greater primary coverts and white underwing on dark scalloped patterns!).