Here is what I do, I am Canadian and I have Canada gesse in my back field. Here geese are easily spooked when on solid ground, they don't seem to care very much when in water. When comming up on geese lower your altitude, you are comming in to high and way too fast. I would stay about 40 feet off the ground and gradually come in slowly. Move up on them and stop for 30 seconds then a bit closer and stop again and so on. Our drones do not resemble any natural predator and if you give them the chance to figure that out you may be able to get close. On land I can get about 30 feet from them as they will walk away. If they are close to water they will walk to it and once in they seem to relax and will tolerate the noisy drone and slowly swim away from you. If you fly after them fast when they are in flight you are now a predator and they will fly away. In the air if you hang back they may land. Like jwmcgrath said if one decides to come after you I garantee your bird is going down. Be slow and gentle and give them time to figure out your just a noisy white bird. When in water if they decide to take off it takes them a long distance to go and you craft is safer, on land if you are too close they will jump for you and take you down.