I'm curious about this because I refuse to try and vent sex Cas. I don't want to accidentally hurt him, or have him become fearful of me. But I am wondering if the head lowering (with or without hissing) type posture is more of a gander behavior than a goose? Or, if early on, it's both sexes equally? Cas will lower his head, sometimes hiss, sometimes not, and charge my kids cat. Which I find hilarious to watch by the way LOLHe doesn't do this to me, or the hub, but will on occasion do this to our ADHD son who's 15 and moves kind of fast. I have read that as they become older, it's easier to tell ganders from geese by their posturing (not 100% accurate though because you can have a more aggresive/protective goose, or a really laid back gander) but I'm wondering if it starts early?