Jizz (birding); the immediately recognisable characteristics of a bird or other organism.
Sean Dooley described jizz as “the indefinable quality of a particular species, the ‘vibe’ it gives off” and notes that although it is “dismissed by many as some kind of birding alchemy, there is some physical basis to the idea of jizz.”
Jizz is used quite commonly by birders in Britain. I don’t know if your brother is British or American but I’d assume it’s just a term that never caught on in America and that’s why your brothers never heard of it?
He’s American. He has traveled to a few other continents for birding adventures, but I doubt that sort of thing would come up, even in birder conversation.
Is jizz as common in Britain as jism or spunk? She said, with a straight face.