A local 4cy bird, ringed E104 left red. Ringed at the nest at Maasvlakte July 17 1999, now in it's 4cy (third summer). The tail consists of third generation rectrices but is completely white. The scapulars are adult-like grey, though a few feathers show an indistinct paler brown hue. In this bird, the median coverts look fresher than the greater and median coverts and lack the brown hue which can be found in (especially) the greater coverts. The under-parts and the head are white. The legs are deep yellow and there is a diffuse bill-band. The black on the bill is confined to the upper mandible and doesn't run back along the culmen towards the base. The red gonydeal spot is confined to the lower mandible. The mirror on P10 is a limited spot, hardly reaching the feather's edges. The inner-hand has the typical immature characteristics, with P4-P5 having a brownish inner-web and p4 has extensive sub-terminal black marking on the outer-web, running to the base along the shaft. P6 has a white tip, but P7-P10 lack white tips on the primaries. The primary coverts can just be seen beneath the greater covert bar and the white tips are obvious.

Although only in 4cy, this dominant male has established a territory in one of the oldest colonies and is paired with the female left (in the bottom picture). However, that's no guarantee for breeding success, and it may take well into their 8cy for some adults to start the first nest.