Mountain bluebirds are one of Yellowstone’s first returning migrant birds. They start to appear in March. Their bright blue plumage stands out in sharp contrast to the snow and dull brown vegetation that prevails in early spring. This male perched on the top of a small lodgepole pine, watching for insects in the early grasses. It was snowing lightly and the cold damp breeze caused both of us to fluff up and try to stay warm.