Anser cygnoides
In the middle of the Los Alamos townsite, we have a small pond that dates back to the days when there was a Ranch School here that was acquired by the government for the Manhattan Project. There is a small group of domesticated water fowl that stay there except in the coldest part of the winter, when the pond freezes over (and then the birds have no way to escape from predators, e.g., coyotes). At that time, there is a small volunteer group that houses them safely until springtime. The numbers of birds fluctuates due to a variety of reasons, predation on the one hand, and abandoned Easter ducks on the other. This is a pair of the longer-term residents, Chinese Geese (one of the brown form and one of the white form). Chinese Geese are a domesticated form of the Swan Goose.