Canada Geese

We appear to have two creches of Canada Geese - three adults appeared to be looking after 22 chicks of various sizes, (the biggest of which were even shoo-ing ducks away!) and seemed to be thoroughly unconcerned by people going right up to them,  but one of them seemed to take against another adult goose.  A seperate group seemed to consist of two geese in charge of twelve goslings - they were slightly less adventurous and got back in the water when a human family approached, but they did have a dog with them so perhaps that is the explanation?