Ground hogs also burrow in the ground and you would not expect to see one climb a tree,but, they have been known to do it. They normaly hibernate in the dead of winter, but, I have seen them out in the snow before.
Actually, I looked more. Several science sites confirmed the info. The geese fly at too high of an altitude and for too long for the hummingbirds to survive the flight. And, as I was realizing, the geese here do not migrate, so the hummingbird would not find them helpful in getting to tropical zones.
Those are easily explainable. Especially the snow. We have had an extremely warm winter, and the bears are coming out.