Ganders can be total a-holes (and that is not a term I use often) during breeding season. Here in the US where I live that is February through April. *raises sleeves to show bruises on arms* They will defend their girls to the death, fight with each other, be noisy at a leaf falling in the wind, attack their reflection in glass (I recently had some antique windows that I had set aside for crafting broken by male geese) and so on. Not all of them, and some breeds are worse than others, but they can be. Doesn't seem to matter if they were hand raised or not. So, if you are thinking of adding geese to your flock be aware that some can turn Jekyll and Hyde on you seasonally. Not all individuals, and some breeds don't as badly, but the same breeds that are more mellow aren't as good as guardians. It always breaks my heart when someone is looking to get rid of geese because they have gone "mean" - even more so if they just want to get rid of the gander because I have heard of gooses who literally starved themselves to death after their gander disappeared. It breaks their heart to be separated. This said, I love my geese and they are my favorite of all of my poultry, I just wish that breeding season would hurry up and be done with.