Mountain Bluebird juvenile

This young Mountain Bluebird was seen when friends, Cathy and Terry, and I, went on a three-day trip (26, 27 and 28 August 2014) down to Waterton Lakes National Park. I can't remember where we saw this little Bluebird - I was thinking it was near the Yellow-bellied Marmots, but that was two days later.

In Bluebirds, the blue colour is produced by the structure of the feather - there is no blue pigment. "Tiny air pockets in the barbs of feathers can scatter incoming light, resulting in a specific, non-iridescent color. Blue colors in feathers are almost always produced in this manner. Examples include the blue feathers of Bluebirds, Indigo Buntings, Blue Jay's and Steller's Jays."

www.allaboutbirds.org/guide/Mountain_Bluebird/id

www.jstor.org/discover/pgs/index?id=10.2307/4077277&i...