No, they are not bluebirds. But they are blue, and they are more than happy to occupy a bluebird house.
The popularity of the bluebird has been a boon to the Tree Swallow, which nests in holes of exactly the same size, and has taken advantage of bluebird houses over much of North America. In regions with no such ready supply of artificial nest sites, the swallows must compete with other cavity-nesting birds, arriving early in spring to stake out territories.
Audubon
You know Mike Foy loves his blue birds and I love this post.
Great photos Dave!
Lindísimo el pájaro Azul, muchas gracias Michael por preocuparse por las bondades que nos da la naturaleza y a su amigo por esas fotos tan maravillosas.