Lots of time in Hants and W.Sussex last couple of months with a survey contract. Managed to find a bit of time today to get record shots of a couple of finds, although all are with coolpix and scope
Spot the Black Brant, click to enlarge
The bird on the left here looks very close to Pale-bellied but did actually have a dark vent area which can just be seen here, though nowhere near as extensive as the usual bird on the right.
Same birds again, the one with very little brown on the underparts has also paler flanks, features getting pretty close to Pale-bellied. This is either an extreme variant or perhaps a hybrid, they have been known to occur.