The sky above the town of Choteau, Montana ... The squawking of birds fills the air. (SOUNDBITE OF BIRDS SQUAWKING) JUHLIN: Lisa Hudnutt, a retired local teacher, quickly sets up a spotting scope.

It's cold, and the infamous Montana wind ... van about the different birds we'd see, and how many geese would be part of the morning takeoff. Fixing the scope towards the center of the lake, Hudnutt ...

Birds receive their colors ... their plumage being as likely to fall out. Carotenoids are a type of pigment that are ...

The sky above the town of Choteau, Montana ... of birds fills the air. (SOUNDBITE OF BIRDS SQUAWKING) JUHLIN: Lisa Hudnutt, a retired local teacher, quickly sets up a spotting scope. Colors ...