In the animal kingdom, only birds grow feathers. As protective coloration, they serve to insulate, assist in flight, and uniquely contribute to a bird's behavior. There are an astonishing 940 individual feathers on a hummingbird. In comparison, there are approximately 25,216 feathers on a whistling swan.

In his studies of smaller birds, Staebler (1941) determined that even though "they have fewer feathers than larger birds, hummingbirds have more feathers per unit of body weight than bigger birds. This may be correlated to their greater need for heat retention and a higher rate of metabolism."

A bird can adjust the position or posture of its feathers, largely by bands of non-striated skin muscles. These "feather muscles" are controlled by the hummer's autonomic system. They can be depressed by a depressor muscle, or raised by an erector muscle, such as the flaring out of the male calliope's purplish red feathered streaked gorget. Feather muscles can also pull feathers together, twist them, or combine these actions for flight, courtship or territorial defense. Other feather muscles appear to aid these tiniest of birds in spreading and closing the feathers of its wings.

There are different types of feathers on each bird. For instance, the design of a tail or wing feather is much different in structure that a fluffy downy breast feather used for insulation. Cruickshank explains, "From an engineering standpoint, a feather is the most complex growth of the skin known to be formed by any animal. It's one of the lightest and simultaneously, one of the strongest materials created by any animal. These interlocking parts of a single feather add up to more than a million individual units, many microscopic in size."

All hummers don reflective feathers, that have no true pigment. The brilliant range of colors of the hummingbird that we observe are not true color at all but the result of the feather's structure and the nature in which it reflects the sunlight back to our eyes. In fact, if these feathers were actually ground up in a blender, the end result would be a grayish, mushy powder. Specifically, the neon-colored gorget of male hummers are composed of yet another type of iridescent feather. The tiny hairlike parts of these flashy throat feathers, called barbules, have flat sides, and when they are twisted or turned just right, the light they refract and reflect is one of specific wavelength, but from other angles, the feathers appear black.

Although feathers seem fragile, they are actually quite tough and resilient; and comprise from 4 to 12 percent of the tiny bird's weight.

Hummers utilize their feathers for insulation. By fluffing their feathers, they can trap air and thus keep out the cold. Conversely, when heat is extreme, these little birds hold their feathers tight against their bodies, squeezing out the air normally trapped there, and in this manner allow any body heat to escape, thus rendering themselves more cool. These same hummers in your yard may therefore appear to be different individuals, but may in fact have only adusted their perceived body size.

These winged jewels are one of the few bird species to hatch completely naked, lacking natural down, and directly evolve into juvenile plumage. In later life, hummers take care of their adult feathers by using their long bills to carfully comb, brush and straighten them. They clean their feathers and keep them groomed with oil they retrieve from the preen gland located at the basal tail feathers. "This waxy oil is critical to extending the life of the hummingbird's feathers and helps make them pliable and waterproof," explains Robert Sargent (1999).

In summation, the feather of a hummingbird is a wondrous creation. "Many people live long, healthy, happy lives without once comtemplating the adaptive nature of a bird's feather," says Laura Erickson.

What a precious gift to acknowledge these curious miracles of Mother Nature. We have only just begun to discover the mysteries of these flying treasures, the hummingbirds.

To view some interesting photos of HYBRIDS and their feathers, visit the Web site www.trochilids.com.

The hummingbird count as of Tuesday was 1,887, which breaks down to 1,244 calliope, 634 rufous, two broad-tailed, four black-chinned and three hybrids.

Editor's Note: The IR is running occasional updates from volunteer hummingbird banders Ned and Gigi Batchelder who are in the Helena area for the summer.