Duck or Goose????

Dustin and I were having a discussion over the birds in the background. (I didn't take another picture of them, sorry). Excuse the bird in the foreground. Are they Ducks or Geese?? I say they are Ducks. Below is a photo of Geese and another type of Duck. DuckDuckGooseBy the way, who knew Seagulls like cold weather, and the Rocky Mountains???? They migrated here once it got cold.