Brown Creeper

Brown Creeper
Although they are primarily an inhabitant of northern coniferous forests, Brown Creepers can also occur anywhere there are large stands of dying timber, with the large peeling scales of bark that Creepers use to shelter their nests. They have been known to move into areas where trees have died from diseases like the Dutch elm disease or from flooding. Such opportunism may result in only temporary population increases, however, and in areas where extensive stands of timber have disappeared with logging, so have Brown Creepers.

The breeding range extends across North America in northern coniferous forests from southern Alaska to Newfoundland. In the eastern United States, south of the northern conifer zone, they are less common, but occur locally along the eastern seaboard from Massachusetts to Pennsylvania, south through the Appalachians, and throughout Mississippi basin floodplain forests and cypress swamps. In the West, they breed from Washington south along the coast to California, and in the Rocky Mountains. They also inhabit the Mexican highlands and as far south as northern Nicaragua. In the Rocky Mountains they are typically seen at high altitudes, as high as the timberline in Colorado.
Brown Creeper Range Map

Males have been observed performing a high-speed display flight among the trees, circling the trunks and weaving in and out of branches, and at times pursuing a potential mate. The song is short, consisting of five or six notes, sweet and delicate, and high-pitched. The song might be rendered phonetically as see-wee-see-see tee-see.

A foundation for the nest of twigs and bark is built behind a loosened bark scale and extended up to close the open sides of the shelter so that the twig and bark base forms a crescent shape. On top of the foundation, a cup of finer bark shreds, grasses, feathers, and mosses is placed. The nest is built entirely by the female, although the male may gather material for her to place. For two weeks, the female incubates five to six eggs, while being fed by the male. Both sexes feed the fledglings, which (after about two weeks) are able to leave the nest and immediately cling to the bark with their sharp claws. The stiff tail that supports the adults when they creep about on the bark is not developed at this stage. Groups of fledglings conserve warmth by roosting together. Adults have also been observed roosting together in the shelter of a hollow limb.

During fall there is a partial withdrawal from the northern parts of the range, as some Brown Creepers migrate south to winter irregularly throughout the United States. During migration, a wider variety of habitats are used, including city parks and open woods, as long as suitable large trees are available. High altitude nesters in North Carolina and in the Rocky Mountains retreat in late fall to valley areas. These birds are commonly seen during winter in the mixed, wet deciduous and mixed forests of the East, in western coastal coniferous forests, in the tree and shrub savannas of Texas, and in riparian forests in grassland areas. Brown Creepers often join mixed-species flocks with chickadees, nuthatches, and woodpeckers.

More-so than its flock-mates, the Brown Creeper relies on insects and spiders and their eggs for winter food, with only occasional use of vegetable food such as acorns, beechnuts, corn, or seeds. They will also come to feeders to feed on suet. In the summer they are exclusively insectivorous, finding food by intently examining bark crevices as they repeatedly spiral up tree trunks, and then fly down to the base of another tree to start again. When foraging higher up in trees, they creep along the underside of branches in search of food.

Description: Brown Creepers are small, long-winged, slender birds with a thin down-curved bill. The are brown above, speckled and streaked with white, and rufous on the tail and rump. There is a white line over the eye. The tail is long, pointed and stiffened at the end for use as a prop when climbing. The underparts are white. In flight they show a conspicuous broad buffy band on the wings. No other North American bird displays the combination of mottled plumage, down curved bill and distinctive upward creeping habits.

Brown plumage, streaked and spotted with buff, gray and white perfectly camouflages Brown Creepers against a background of bark. When threatened by a potential predator, they will freeze, often with outspread wings, and remain motionless for several minutes. At such times they can be nearly invisible.