Species Profile
Brown creepers are inconspicuous birds whose intricately patterned backs help blend them in with the tree bark that is their near perpetual home. Creepers blend into the forests where they live. Brown creepers breed across a huge range extending from Alaska east across southern Canada to Newfoundland and south through the United States to Nicaragua in Central America. They favor larger, closed-canopy forests with many large trees for foraging and nesting, especially trees with deeply furrowed, loose or flaking bark. Although uncommon and rare, the species is widely distributed in heavily forested regions of Pennsylvania. It is one of the birds that are considered “area-sensitive” forest species that live in unfragmented forest tracts. Breeding Bird Surveys show that their numbers are lower in the state’s southeastern and southwestern corners. Braced by their long stiff tails, brown creepers climb slowly up tree trunks, following a spiral course. They inspect bark furrows and niches, using their decurved bills to tease out insects, pupae and eggs. They also eat spiders and seeds.
The call is a long, thin seeee; the male also voices a subtle and high-pitched, but beautiful breeding song. As part of their courtship, creepers do a spiraling chase flight around tree trunks. In some flights, they seem more like falling brown leaves than live birds. The species nests under peeling bark, often in a shagbark hickory or a dead or dying tree, less frequently in a cavity.
A hammock-like twig nest is built to fit the available space. The female lays four to eight eggs, which are whitish and dotted with reddish brown. Incubation takes 13 to 17 days, and young leave the nest 14 to 20 days after hatching. Brown creepers from the Northeast may migrate south to Florida and the Gulf Coast. In winter, brown creepers sometimes mix in with foraging flocks of chickadees; perhaps these are residents, or northern birds that have shifted southward.
