Montana Field Guide

Brown Creeper - Certhia americana

The only tree creeper in North America. Begins at the base of a tree and climbs upward, sometimes spiraling around the trunk until it nears the top. Very small, male: 12.0-13.5 cm; female:11.7-13.2 cm. Average body mass for both 7.2-9.9 g. Adult plumage, dark-brown upperparts, extensively streaked with dull whitish on head, back, scapulars, and wings; distinctive brownish-white supercilium. Underparts whitish washed with cinnamon distally. Tail long and stiff. (Hejl, Newlon, McFadzen, Young, and Ghalambor, The Birds of North America, No. 669, 2002).

Montana Range

In Bozeman area vertical movements and/or migrations occur Feb 20-Apr 20 and Sep 10-Oct 30.

Late successional stages of coniferous forests and mixed coniferous-deciduous forest. Especially common in unlogged, old-growth stands. The consistent factor appears to be the need for large trees and snags (dead trees) for foraging and nesting microsites (Hejl, Newlon, McFadzen, Young, and Ghalambor 2002).

Forages primarily on trunks of live trees. In winter main foods taken include a variety of insects and larvae, spiders and their eggs, ants, and pseudeoscorpions; a small amount of seeds and other vegetable matter. Breeding season is the same as winter, but possible no vegetable matter is eaten (Hejl, Newlon, McFadzen, Young, and Ghalambor 2002).

Nest built in 2 parts, base and nest cup, behind a piece of peeling bark. Subelliptical eggs are white, speckled with pink or reddish-brown. Clutch size is usually 5 or 6 (Hejl, Newlon, McFadzen, Young, and Ghalambor 2002). Nesting periods probably similar to those found in Black Hills (mid-May to mid-Jul) and to those found in Rocky Mtn. NP (Jun and Jul).