Photo 10: LBBG 3cy, May 26 2000 Naaktstrand, Maasvlakte, the Netherlands. 

Third and second summer side-by-side and in these individuals ageing is very straightforward. Note e.g. the differences in patterning and coloration of primaries, tail, upper-parts and coverts. But one should bear in mind that especially advanced second summers with moulted coverts, upper parts and tail feathers resemble third summers. In such a case it is important to take notice of the pattern of the primaries. Whereas third summers usually show a white mirror and conspicuous white tips to at least the inner primaries, second summers normally have brownish toned primaries without sharply demarcated white tips and often with pale brown inner primaries. The variation in coloration of the inner primaries of second summers is large. Generally, the coloration of the inner primaries is dark brown, but in the depicted bird it's quite pale.