Clayton, North Carolina

Birds Adapt As Season Turns

As the seasons change, so do the feathers, songs and behavior of many of our favorite backyard birds.

In the spring, bird plumage, particularly males, are at their brightest. The brilliant yellow of many warblers and finches, the bright blues of jays and indigo buntings and flaming reds of cardinals and tanagers can't help but catch our eyes and those of the females of the flocks. Although several species retain their distinctive colors year 'round, even those birds appear much brighter in the spring than in the fall.

Bird songs also are different at different times of the year. They too are meant either to attract a mate or stake out a territory. In the spring birds are very vocal, and each species has a distinct song or call. Animosity will occur between birds of the same species as males challenge each other throughout the breeding season.

Once spring turns to summer, mates are chosen, nests built, eggs laid and hatched, and nestlings demand food. Other than territorial warnings, the birds are quieter, using all of their energy tending the nests and searching for food for their young.

Although young fledglings may look just like the adults, juveniles are easy to identify because they still beg for food. You often see one perched next to its parents on a branch or on the lawn, standing with mouth agape and wings shivering in a begging attitude.

By late summer to early autumn, birds molt and the new feathers come in more subdued in color. Most notable is the male goldfinch. He sheds his bright yellow breeding feathers which then are replaced by a duller olive green, making him resemble the female.  Not all birds migrate, but all do "molt." Feathers are key to birds' lives and must be in good shape for birds to remain healthy and to manage arduous travel. Most of our feeder birds molt once a year, usually beginning in late summer after all the breeding is finished. Molting is a gradual process of losing feathers and replacing them with strong new ones a few at a time. When birds molt, the feathers usually fall out symmetrically on either side of the body, a few at a time. Although gaps appear, the birds still are able to fly but may temporarily lose some ability to maneuver quickly. Year 'round residents, such as chickadees, cardinals, jays and woodpeckers, add thousands of insulating down feathers to help keep them warm during the winter. Among the migrants, scarlet tanagers fade from brilliant red to greenish-yellow and many warbler species lose their distinctive markings by the time migration begins.

As the days of summer become shorter, the diminished daylight signals that it's time again to be on the wing. Migrations are determined by geography, weather and availability of food. Some hearty warblers stay until October, feeding off berries and seeds. The phoebe leaves when its supply of insects runs out, but the robin stays longer because it switches from worms and grubs to late berries. In some places, another migrant moves in as others depart. For example, some songbirds leave their northern breeding grounds just as juncos arrive from even farther north. White-throated sparrows that nest from northern Wisconsin, across most of Canada up almost to the Arctic Circle winter from Illinois and New York south to the Gulf States. These winter visitors will help you clean up your fall garden if you let some of the wilted plants go to seed. They will pick off any remaining flower heads along with the millet you provide on your platform feeders. You may notice a heavy increase in activity at your feeding stations as birds flock in preparation for migration. While fall feeding can help to enlarge the bird population in your neighborhood, the availability of food will not induce migratory birds to remain behind.

As summer wanes, adults and young of some species alter their routine and join with other families in small flocks. For example, tufted titmice and Carolina chickadees belong to the same family but often form a mixed flock that also can include goldfinches, nuthatches and downy woodpeckers. Traveling together and watching each other, individuals notice when another member of the flock finds food. Its feeding behavior leads the rest to claim their fair share. Another group benefit is that many birds can spot danger quicker than one bird can.

By inviting the birds into your backyard, you get the opportunity to catch glimpses of their lifestyles as the seasons come and go. You hardly need a calendar to know September has rolled around again, simply because you see the changes in your feathered friends.