One less Mountain Bluebird

We came across this part of a wing belonging to a Mountain Bluebird when we were on a walk in a local park.

"The colors in the feathers of a bird are formed in two different ways, from either pigments or from light refraction caused by the structure of the feather.

The blues seen in the feathers of Bluebirds are structural colors - there is no blue pigment.

First, observe the feather in normal lighting conditions and you will see the expected blue color. Next, try back-lighting the feather. When light is transmitted through the feather it will look brown. The blues are lost because the light is no longer being reflected back and the brown shows up because of the melanin in the feathers." From www.birds.cornell.