This is not always the case. 7 years ago I rescued a gander sitting on the side of the road mourning his dead mate who I am guessing had been hit by a car then eaten by hawks. Anyway that gander decided after about 3 or 4 weeks at most that he was going to 'marry' a Pekin runner X duck who hatched ducklings shortly after his arrival. A year later I got a female goose, who he completely ignored. 7 years later he is still dedicated to his duck wife, who I have never seen him have sex with) and he vigorously guards any ducklings that are hatched from any threats or perceived threats. As far as I am aware he was raised with other pilgrim geese and not around ducks at all prior to coming to me. He can also fly perfectly well but has only done so twice in the 7 years, both times when his duck wife was somewhere that meant there was a fence between him and her (and an open gate but he didn't see that lol). I'm not sure whether the ducks are all geese and goslings in his mind or he thinks he is a duck (absolutely head duck, lol) but he is 100% committed to and engaged with all of the ducks and considers ever ducklings that hatches to be one he must have personally sired. I have been working from home all of the 7 years till the last 6 months and he has not ever become sexually aggressive towards the ducks. He would mate the goose when she was in lay but that's the only action he has ever tried to get apart from once with a khaki Campbell which was never repeated, and a couple of times this last spring with a very willing Muscovy hen(lol). He's a complete dick to me during spring but the ducks are his family and his flock and he'd never force or harm them. In fact for a while he was really useful in going and firmly but gently (as in hard enough to sting but not injured) any Drake's who got too aggressive with ducks during spring. Last couple of years he has not been useful most the time with that. Possibly he is getting on as I'm not sure of his age. My biggest worry now is his duck wife is 8-9 years old and if he's not much older then life spans mean he's going to lose her and be devastated...
He is useless at chasing off hawks but I suspect the reason that no ducklings have ever been taken by hawks is he would probably defend them.
He is useless at chasing off hawks but I suspect the reason that no ducklings have ever been taken by hawks is he would probably defend them.