Males and females are similar in appearance with brown upperparts that are streaked with white, white underparts, a white line above their eyes, and slender, down-curved bills. Although they are unremarkable in appearance, their behavior is quite interesting. Their long, stiff, pointed tail is used as a prop while climbing trees. Brown creepers can be observed hopping up tree trunks looking into crevices and spiraling upward until they reach the top before fluttering down to the base of the next tree. They do not move sideways or down tree trunks as nuthatches do. They are small, slender birds, about only five to 5.75 inches in length with a long wingspread of seven to eight inches. Weights range from 0.25 to 0.33 of an ounce. Brown creepers utter faint hss notes as they climb up the trunk of a tree. They also produce a zi-i-i-it note that sounds like a small steel chain falling into a heap. They rarely sing in migration, but on nesting grounds, they utter a high-pitched musical song. Brown creepers are also known as: American brown creeper, American creeper, California creeper, common creeper, little brown creeper, Mexican creeper, Rocky Mountain creeper, Sierra creeper and tree creeper.
Range: Breeding occurs from Alaska through Ontario to Newfoundland, south throughout the western mountains, the Great Lakes area and New England. Winters are spent in much of their breeding range south to the Gulf Coast and Florida. Brown creepers occupy all coniferous forests and woodland habitats in Colorado from ponderosa pine to sub-alpine spruce/fir. They generally breed among mature spruce/fir and lodgepole pine from 9,000 to 11,500 feet. Brown creepers are year-round residents, but move to lower elevations during winter months.
Habitat: Brown creepers prefer dense, mature conifer stands, but they can also be found in hardwood conifer, montane forests and deciduous riparian habitats. They require rotten snags, dead trees with loose bark, and stumps for reproduction and cover.
Diet: They forage on large diameter trees by spiraling upward along the trunk and out onto the branches for insects, spiders and larvae. They also eat a small amount of mast, nuts and seeds. They will visit feeding stations for chopped peanuts or peanut butter-corn-meal-suet mixtures that are placed in the bark of trees.
Reproduction: They are solitary birds outside of the breeding season, but they pair up when mating occurs. Brown creepers are monogamous and will breed from mid-May to mid-June. Nest sites are located five to 15 feet above the ground. They suspend hammock-like nests behind a large strip of bark still attached to a living or dead tree, or within a tree cavity. Both the male and female build the nest, which consists of a loose cup of twigs, moss, and grasses, lined with feathers and fine bark. The female will lay four to eight white eggs that are sparingly dotted with browns and incubate them for 14 to 15 days. The young are altricial (naked and helpless) when they hatch, and are cared for by both parents. They leave the nest when they are about two weeks of age, at which time they can only fly weakly but can climb well
For more information, see the Natural Diversity Information Source species profile.