Braunbaumläufer

Bestimmung

Adults are brown on the upper parts with light spotting, resembling a piece of tree bark, with white underparts. They have a long thin bill with a slight downward curve and a long stiff tail used for support as the bird creeps upwards. The male creeper has a slightly larger bill than the female. Brown creepers are smaller than white-breasted nuthatches but larger than golden-crowned kinglets.<p>Measurements:<p>Its voice includes single very high pitched, short, often insistent, piercing calls; see, or swee. The song often has a cadence like; pee pee willow wee or see tidle swee, with notes similar to the calls. Creepers in California have songs of four to nine syllables, except in the San Bernardino Mountains, where there are as many as nine to thirteen syllables per song, but within the same two second time frame.<p>This species's avoidance of edges, cryptic plumage, and high-pitched vocalizations contribute to a low survey detection rate compared to other species.

Taxonomie

Wissenschaftlicher Name

Certhia americana

Autorität

Bonaparte, 1838

Ordnung

Passeriformes

Familie

Certhiidae

Gattung

Baumläufer

Verbreitung und Lebensraum

Zugverhalten

Complete migrants

Verhalten

Brown creepers forage on tree trunks and branches, typically zig-zagging upwards from the bottom of a tree trunk, and then flying down to the bottom of another tree. They creep slowly with their body flattened against the bark, probing with their beak for insects. They will rarely feed on the ground. They mainly eat small arthropods found in the bark, but sometimes they will eat seeds in winter.

Schutzstatus

The species has declined in much of North America but appears to be doing well in Washington, with a small (not significant) increase on the state's breeding bird survey since 1966. As with many of Washington's birds, the Cascades divide this species into two subspecies.<p>In Wyoming, brown creepers have been recognized as preferring habitat within large, intact and mature stands of spruces, firs, or lodgepole pine. It is therefore potentially vulnerable to logging, climate change, or replacement of those tree species by Ponderosa pine. However, it is not considered a species of serious concern in that state.<p>In New Brunswick, brown creepers have been shown to respond negatively to even moderate forestry. Conservation efforts in the province have focused on maintaining unmanaged patches with high densities of trees and snags in mature forest.<p>Ivory-billed woodcreepers (Xiphorhynchus flavigaster) have been observed extracting brown creeper nestlings and dropping them away from the nest.

Bestandstrend

rising