Nazgul: The fisherman's friend

Love 'em (like our resident Cormorant guru) or hate 'em (let's not go there) you can't ignore 'em: Nazgul are here to stay! [For the Tolkien-refusers amongst you, they're the improbable winged black dragony things that make a nuisance of themselves by trying to gobble up hobbits and the like]. The disappointing thing about today's motly gang is that sinensis is a) not safely IDable on extent of white on head - and I can never remember the Cormorant Coefficient Calculation when I need it - and b) not tickable anyway...