Creepers are among the most inconspicuous birds in North America. Embracing old coniferous forests, the Brown Creeper often goes unnoticed until a flake of bark appears to come alive. The Brown Creeper forages by spiraling up trunks. Once it reaches the upper branches, the creeper floats down to the base of a neighboring tree to begin another ascent. The thin whistle of a Brown Creeper is so high-pitched that it is frequently not heard by birders. There are many species of creepers in Europe and Asia, but the Brown Creeper is the only one found in North America.
I.D.: Sexes similar: brown back is heavily streaked with grayish white; white eyebrow; white underparts; downcurved bill; long, pointed tail feathers; rusty rump.
Size: L 51/4 in. (13 cm).
Range: common resident in the southern and central U.S. Rockies; uncommon but regular in the northern U.S. Rockies; uncommon year-round in the Canadian Rockies.
Habitat: mainly coniferous forests, such as spruce, fir, limber pine, lodgepole pine and Douglas-fir, up to the lower subalpine.
Nesting: under loose bark; nest is made with grass and conifer needles woven together with spider silk; female incubates 5-6 eggs for 15-17 days.
Feeding: hops up trunks and large limbs, probing loose bark for adult and larval invertebrates.
Voice: faint, high-pitched trees-trees-trees see the trees.
Similar Species: Nuthatches: all have a gray-blue back. Black-and-white Warbler: black-and-white plumage; shorter tail. Woodpeckers: all lack the brown back streaking and have a straight bill.