Blue birds inhabit diverse regions worldwide ... blackish wings and tail, distinctive beak, and rufous wing bars. Male Indigo Buntings are bright blue with dark wings during breeding and browner ...

Under these drastically changing conditions, the struggle to survive favored the larger birds with deep, strong beaks for opening the hard seeds. Smaller finches with less-powerful beaks perished.

D espite their colorful appearance, blue jays are actually in the genus corvidae, the same as crows and ravens. These birds are typically 9 to 12 inches long from beak to tail and weigh under 3.5 ...

But blue feathers result from refraction ... At the river's edge two birds will lock beaks and attempt to force each other underwater. Breeding season requires a pause in the usual hostilities ...