Welcome to the Birds of North America Online!
Welcome to BNA Online, the leading source of life history information for North American breeding birds. This free, courtesy preview is just the first of 14 articles that provide detailed life history information including Distribution, Migration, Habitat, Food Habits, Sounds, Behavior and Breeding. Written by acknowledged experts on each species, there is also a comprehensive bibliography of published research on the species.
A subscription is needed to access the remaining articles for this and any other species. Subscription rates start as low as $5 USD for 30 days of complete access to the resource. To subscribe, please visit the Cornell Lab of Ornithology E-Store.
If you are already a current subscriber, you will need to sign in with your login information to access BNA normally.
Subscriptions are available for as little as $5 for 30 days of full access! If you would like to subscribe to BNA Online, just visit the Cornell Lab of Ornithology E-Store.
“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.” Tyler 1948: 56
One of the continent’s most inconspicuous songbirds, the Brown Creeper is the only treecreeper in North America. Its cryptic coloration and high-pitched vocalizations make it difficult to detect, yet its distribution is widespread in coniferous and coniferous-deciduous forests throughout North America from Alaska and Canada south to northern Nicaragua. In its endless pursuit of bark-dwelling invertebrates, it begins at the base of a tree trunk, climbs upward, sometimes spiraling around the trunk until it nears the top, then flies to the base of a nearby tree to begin the process again. This creeper uses its slender, decurved bill to glean invertebrates—mainly insects, spiders, and pseudoscorpions—from furrows in the bark. It was not until 1879 that naturalists discovered its unique habit of building its hammock-like nest behind a loosened flap of bark on a dead or dying tree.
The sole representative of its family in North America, the Brown Creeper is almost indistinguishable from its Old World counterpart, the Eurasian Treecreeper (Certhia familiaris), and they were long considered conspecific. The systematics of treecreepers remains somewhat uncertain, but studies of vocalizations indicate that Brown Creeper and Eurasian Treecreeper should be treated as a separate species.
Although the Brown Creeper is found in a variety of forest habitats, it favors closed-canopy forests with an abundance of large dead or dying trees for nesting and large live trees for foraging. It is most abundant in mature and old-growth forests in summer but uses a wider variety of wooded habitats (deciduous forests, suburbs, parks, and orchards) in winter. In recent decades, numbers in New England have increased, possibly as a result of reforestation, the widespread mortality of trees due to gypsy-moth (Lymantria dispar) invasion, and mortality of American elms (Ulmus americana) due to Dutch elm disease. Apparent expansion of breeding range in mid-Atlantic states, Midwest, and California, but local extirpations due to habitat loss in New York, Michigan, and lower Colorado River Valley. This creeper is often considered a year-round resident throughout its breeding range, but northern and high-altitude populations migrate. It is territorial during the breeding season, but in winter, often joins mixed-species foraging flocks and roosts communally with other Brown Creepers.
Populations of this species have declined since presettlement times in northwestern Douglas fir (Pseudotsuga menziesii) forest owing to loss of mature and old-growth trees (Raphael et al. 1988) and in southwestern ponderosa pine (Pinus ponderosa; Brawn and Balda 1988) due to loss of mature pines. Current population-trend information indicates the species is stable in most areas in North America. Current U.S. Fish and Wildlife Service Breeding Bird Survey (BBS) trend data, however, should be viewed with caution because of the low number of individuals counted on routes and biases associated with roadside surveys. It is highly likely that creeper numbers have continued to decline in the West because of timber-harvesting practices. Degradation of habitat via the harvesting of large, live trees, salvage-logging practices that remove dead or dying trees, and the increasing fragmentation of forests, particularly in western North America, are the greatest known threats to current populations. Loss of large trees to exotic insects and diseases and the eventual loss of large snags in eastern forests could also affect creepers negatively. Partners in Flight groups are concerned about Brown Creepers in Washington, Oregon, California, Idaho, Montana, and the southern Blue Ridge and Allegheny Mountains because of the negative effects of logging and forest fragmentation and the association of this species with large trees and a rare community type.
Despite the Brown Creeper’s widespread distribution, more research is needed on almost every aspect of its biology, especially for Mexican and Central American populations. Key studies of this species include a comprehensive nesting study (Davis 1978), geographic variation in song (Baptista and Johnson 1982), song analysis and taxonomic relationships (Baptista and Krebs 2000), systematics (Webster 1986, Unitt and Rea 1997), foraging ecology (Franzreb 1985, Morrison et al. 1987a, Lundquist and Manuwal 1990, Weikel and Hayes 1999), and habitat use and requirements (Raphael and White 1984, Mariani 1987, Siegel 1989, Mariani and Manuwal 1990, Keller and Anderson 1992, Adams and Morrison 1993, Freemark et al. 1995, Hejl et al. 1995).
Hejl, S. J., K. R. Newlon, M. E. Mcfadzen, J. S. Young and C. K. Ghalambor. 2002. Brown Creeper (Certhia americana), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu/bna/species/669