J Glossary of bird terms
also gestalt, of term may corruption (or possibly deriving air force acronym giss general impression of size , shape (of aircraft) , associated world war ii lingo; though derivation may anachronistic jizz first used in birdwatching 1922), describes overall impression or appearance of bird— indefinable quality of particular species, vibe gives off —garnered such features shape, posture, flying style or other habitual movements, size , colouration combined voice, habitat , location. example use: had jizz of thrush, couldn t make out kind.