Bluebird morning

I went out this morning to look for the Trumpeter Swan family that I saw yesterday (when I didn't have my camera along...). I couldn't find them but I did stumble across a flock of bluebirds cavorting in the weeds next to the "swanless" lake. Bluebirds make good subjects for bird photography because they pause once in a while to look around and see what they want to chase next. Some of their chosen perches were well within the range of my zoom lens in some very photogenic scenery.

How's this for a little fall color matching?

Males still sport the bright blue color on their heads, wings, and tails, which contrasts sharply with the ruddy brown color of the breast feathers. You might not realize that there is no blue color pigment. Instead blue is a "structural color", meaning that it is produced by the feather structure itself. Tiny particles in the feather (smaller than the wavelength of red light) scatter only the shorter light wavelengths in all directions. Thus blue color is reflected from the feather at almost all angles from which it is observed.

Bluebirds like to hunt from a perch, diving into the weeds to chase insects, or hovering above them like a flycatcher. Knotholes on the pines made excellent perches for these hover hunters this morning.

Eastern bluebirds like these seem to be quite common here in the upper Midwest, thanks to the efforts of landowners and park managers who have installed "bluebird boxes" near their ponds and lakes. These artificial nesting holes boosted the bluebird breeding population, which was unable to compete successfully with introduced House Sparrows for natural nest cavities. Typically two "bluebird boxes" are installed about 30-40 feet apart in fields or woods near a source of water. Why two boxes? To insure that there is at least one box for the bluebirds, while the other may be taken by Tree Swallows, Chickadees, House Wrens, or House Sparrows. These species are more likely to tolerate close presence of a different species than one of their own kind.