Ravens do as well in the hot southwest as they do in the cold north. If the color black absorbs heat, shouldn't the bird's black feathers pose a cooling problem? Actually, blacks feathers help with cooling.

The heat absorbed by black feathers -- and heat is absorbed -- is concentrated on the feather surface where the slightest breeze can blow it away. White feathers also collect heat, allowing it, however, to penetrate more directly to the skin where it is more difficult to disperse.

Think of desert tribes and their flowing black robes. There has to be a reason.

This information was one of the notes offered today (Dec. 26) by BirdNotes, a collection of podcasts and short text pieces sent to subscribers via email. It includes photos of the subject bird, and recordings of that bird's vocalizations. BirdNote began in Seattle 10 years ago. It now functions as a non-profit known as Tune in to Nature.org. There is an extensive show archive with many fascinating stories about many fascinating birds. BirdNote also is on FaceBook and Twitter.

Subscribe by email -- birdnote.org

Bird species or related items visited in this set of notes are Common Raven, Sandhill Crane, winter birds of South Florida, pelicans, bird feet in winter, morning in Oaxaca, Mexico, and comments on why we should care about birds. Check this link -- http://bit.ly/1Jzepb7

Below, a Common Raven in the Arizona desert. (Photo by Jim Williams)