a group of greylag geese

aves avian avifauna beak bill bird birding blooded blue branta brown cago canada canadensis chordata close eating ecology endothermic environment feathers feeding feet fowl geese goose grass greylag group head hiding homeothermic lake large ornithology pond preening resting shot sleeping tachymetabolic tucked vertebrate warm water waterfowl webbed weed white wildlife zoology