Photo 4: LBBG sub-adult, Nachtegalenkeet, Maasvlakte, the Netherlands, April 12 2001. 

Probably a 4cy male moulting to third summer plumage. In some respects it is quite adult-like, including a completely white tail. The mirror on p10 is just a small white spot and many of the coverts and scapulars are immature brown. Some adult LBBG in the colony show a reduced bill-band in April, but hardly as obvious as this one (For certain aged adults with bill-band, see the adult section). Sub-adult LBBG turn up in the colony, but are definitely not tolerated by the adults. Adults have to be careful, especially when eggs are laid. The sub-adults try to steal eggs, and after hatching, they even try to take nestlings from related LBBG, probably food supply falls short. Other preys to look for in the colony are young rabbits and sub-adults can be found waiting patiently near rabbit holes.