Why Are Bluebirds Blue?

It's a trick of the light!

A sure sign of spring, is the arrival of the Mountain bluebird. More brilliant in blue than its cousins the Eastern and Western bluebird, this bird’s

BRILLIANT BLUE - Mountain Bluebird

Bluebird - Wikipedia

The Bluebird of Happiness - Big Sky Journal

Creature Feature: Eastern Bluebird

Why are bluebirds blue? - Quora

Franklin County (PA) Gardeners: April 2010

Eastern bluebird - Wikipedia

Top 4 Keys to Having Bluebirds in Your Yard

Blue Birds - Are They True? - Bird Buddy Blog

Bluebird 101: All About Bluebirds - Expedition Wildlife

Why are bluebirds blue? - - Bluebird Information and Resources

Manitoba Breeding Bird Atlas - Atlas des oiseaux nicheurs du Manitoba

Why don't birds have blue pigment? : r/NoStupidQuestions