The Brown Creeper is a tiny forest bird that spends most of its time on the trunk bark of conifer trees. It is a resident species of Edmonds and all of the Puget Trough. Its mottled brown plumage allows it to blend in almost completely with the bark, so is only noticed either by its calls or its movement. It can be seen in any of the forested parks of Edmonds as well as in neighborhoods that retain their Douglas firs and other native conifers.
There are some fun descriptions of this creeper by nature writers. Pete Dunne has this to say: “North America’s only creeper. A tiny, slender, barklike shard of a bird that resembles an emaciated wren and hitches itself up tree trunks like a hyperactive jerky woodpecker.” Naturalist W.M. Tyler wrote this in 1948: “The Brown Creeper, as he hitches along the bole of a tree, looks like a fragment of detached bark that is defying the law of gravitation by moving upward over the trunk, and as he flies off to another tree he resembles a little dry leaf blown about by the wind.” Birding expert Kenn Kaufman describes this bird as a piece of bark coming to life.
The Brown Creeper feeds mostly on insects, especially eggs and pupae hidden in bark. It climbs trees slowly, spiraling up the trunk with its tail braced against the surface, examining the bark and probing into crevices to find its prey. It will eat some seeds and will feed on suet or peanut butter mixtures.
The male defends its breeding territory with song. In courtship, the male performs rapid twisting flights among trees and may pursue a female in the air or around tree trunks. The preferred site for the nest is behind a large strip of bark still attached to a tree. It can be anywhere from fairly low to over 50 feet above ground. The male brings materials and the female builds a hammock-like nest. It is made of bark strips, twigs, leaves, and moss. It is lined with finer materials.
The female lays four to eight eggs and incubates them for about two weeks. The male feeds the female during this time. Both parents feed the nestlings. The young leave the nest about two weeks after hatching.
A resident or short distance migrant, the Brown Creeper is usually seen alone. In migration it occasionally forms small flocks that rarely number more than six. An apt collective noun for this creeper, that spirals its way up a trunk as it forages, is spiral. If you see two or more Brown Creepers, you can refer to them as a spiral of creepers.
The Brown Creeper needs mature forests. It declined as a breeding bird in much of the Eastern U.S. with the cutting of forests. Edmonds is fortunate to still host this species as a breeding bird. Because of its need for mature trees, wildlife managers use the Brown Creeper as an indicator species to gauge the effects of logging on wildlife habitat. Logging that fragments forests poses a threat to the creeper. So does clearcutting and selective cutting that removes large live trees. These are the trees on which the creeper forages. The Brown Creeper is not found in young forests or tree plantations because those trees lack the thick, creviced bark in which it finds food.
The oldest known Brown Creeper was at least 5 years and 5 months of age when it was recaptured and re-released during Illinois banding operations. The Brown Creeper population, estimated at 9.3 million, remained stable or increased slightly between 1966 and 2015. Thus, its conservation status is that of least concern.
You can listen to Brown Creeper calls and song here; http://www.xeno-canto.org/350752.
— By Carol Riddell
Carol Riddell manages the bird education displays, on behalf of Pilchuck Audubon Society and Edmonds Parks & Recreation, at the Olympic Beach Visitor Station.