Grey lags are also the basis for breeds of domestic geese and the appearances are similar. Even though Canada geese are not true geese, they are in the Brant family they have interbred with domestic geese on occasion which makes for some interesting looking birds that have people scratching their heads. Since Grey Lags are very big heavy birds they aren't the best fliers. They were also brought to the US a long time ago for breeding for food because they are big so it isn't out of the question that you may see one.