Photo 1: LBBG sub-adult,  November 26 2000, Westkapelle, the Netherlands.

Some sub-adults are hard to age correctly and are best labeled "immature". Here, the large amount of black, almost the entire basal half, suggests 3cy or at most 4cy. The primaries are in line with what can be expected in 3cy LBBGs, small primary tips at the inner primaries and almost lacking primary tips in the outer four primaries. Nevertheless, the upper-parts are very adult-like with almost all scapulars, coverts and tertials adult-grey. The tail-feathers have been replaced by all-white feathers and the mirror on p10 is well-developed (larger than on average for 3cy LBBG).