The Brown Creeper prefers forests with many large live trees for foraging and large loose-barked (often dead or dying) trees for nesting. In the summer it tends to live in mature coniferous forests; the tree species vary greatly across its range, but can include redwood, Douglas-fir, ponderosa pine, spruce, eastern hemlock, white pine, and bald cypress. In the winter it uses a wider variety of wooded habitats from deciduous forests to suburbs to parks to orchards. In winter in north Texas and the Midwest, creepers are particularly common in oak-hickory forests and tree savannas. Brown Creepers breed up to about 4,500 feet elevation in eastern North America and all the way up to treeline (around 11,000 feet) in parts of the West.Back to top
In the breeding season, Brown Creepers eat insects and their larvae (including stinkbugs, fruit flies, gnats, beetles, weevils, bark beetle parasitoids, butterflies, moths, lacewings, caddisflies, scale insects, leafhoppers, katydids, flat-bugs, plant lice, ants, and sawflies) along with spiders, spider eggs, and pseudoscorpions. They mainly patrol large, live trees with deeply furrowed bark, which harbors the highest densities of insects. They glean, probe, and peck at the trunk with their long, downcurved bills. Starting near the bottom of the trunk, they work their way up the tree to within several feet of the top, then fly to the bottom of another tree (or sometimes the same one) to begin again. In the winter they maintain the same diet of insects and other arthropods, but may also eat small amounts of seeds and other plant materials. Creepers may visit seed and suet feeders. Back to top
Both adults investigate several possible nest sites. They almost always choose a spot between the trunk and a loose piece of bark on a large, dead or dying tree—either deciduous or coniferous—in a dense tree stand. They occasionally nest in large live trees with peeling bark or in dead portions of live trees. Nests are between a couple of feet off the ground and 40 feet up.
The female takes a week or two to build the nest, while the male helps by bringing nesting material (he often sings nearby). She builds the frame of the nest by layering twigs and strips of bark. She uses insect cocoons and spider egg cases to stick those materials to each other and to the inner surface of the tree bark. The nest cup, up to 2.5 inches deep and 6 inches across, consists of wood fibers, spider egg cases, hair, feathers, grass, pieces of leaves, lichens, and mosses. Some of the materials may be used twice, once to build the base and later taken from the base to build the nest cup.
|Clutch Size:||5-6 eggs|
|Number of Broods:||1 brood|
|Egg Length:||0.6-0.6 in (1.5-1.6 cm)|
|Egg Width:||0.5 in (1.2 cm)|
|Incubation Period:||13-17 days|
|Nestling Period:||14-20 days|
|Egg Description:||Smooth and white, speckled with pink or reddish-brown.|
|Condition at Hatching:||Eyes closed and bodies almost completely naked except for long, dark-gray down on the head.|
The Brown Creeper spends most of its time spiraling up tree trunks in search of insects. It holds its short legs on either side of its body, with the long, curved claws hooking into the bark, and braces itself with its long, stiff tail. Both feet hop at the same time, making the bird’s head duck after each hop. Because of its specialized anatomy, the Brown Creeper rarely climbs downward: once high in a tree, it flies down to begin a new ascent at the base of a nearby tree. During breeding season, males have intense singing competitions to establish and defend territories of 5–15 acres. Males fly in fast spirals when pursuing a potential mate. Creepers are probably monogamous, with partners staying together until several weeks after the chicks fledge. Both parents may feed the fledglings. Territories break down late in the breeding season, and in the winter creepers often roost communally and join flocks with other species to forage. Adults may be preyed upon by domestic cats and Northern Shrikes, among other predators. Nests are in danger from red squirrels, northern flying squirrels, golden-mantled ground squirrels, wood rats, and deer mice. When adults see or hear a predator, they freeze, silently pressed against the bark. Creepers have been seen chasing chipmunks and joining groups of nuthatches and kinglets to mob jays.Back to top
Brown Creeper populations were stable or slightly increased between 1966 and 2019, according to the North American Breeding Bird Survey. Partners in Flight estimates the global breeding population at 11 million and rates them 8 out of 20 on the Continental Concern Score, indicating a species of low conservation concern. Timber harvesting in the West, including both clearcutting and selective cutting, has removed many of the large, live trees in which creepers forage, and salvage-logging has removed many of the dead and dying ones they nest in. Forests are also becoming more and more fragmented, posing another threat to creepers. Populations may have increased in New England in recent decades, possibly because forests have regrown and many large trees have been killed by spongy moths (formerly known as gypsy moths) and Dutch elm disease, creating nesting habitat. Spraying of DDT to combat Dutch elm disease in the 1950s may have harmed Brown Creeper populations.Back to top
Lutmerding, J. A. and A. S. Love. (2020). Longevity records of North American birds. Version 2020. Patuxent Wildlife Research Center, Bird Banding Laboratory 2020.
Partners in Flight. (2020). Avian Conservation Assessment Database, version 2020.
Poulin, Jean-François, Émilie D'Astous, Marc-André Villard, Sallie J. Hejl, Karen R. Newlon, Mary E. McFadzen, Jock S. Young and Cameron K. Ghalambor. (2013). Brown Creeper (Certhia americana), version 2.0. In The Birds of North America (P. G. Rodewald, editor). Cornell Lab of Ornithology, Ithaca, New York, USA.
Sauer, J. R., D. K. Niven, J. E. Hines, D. J. Ziolkowski Jr., K. L. Pardieck, J. E. Fallon, and W. A. Link (2019). The North American Breeding Bird Survey, Results and Analysis 1966–2019. Version 2.07.2019. USGS Patuxent Wildlife Research Center, Laurel, MD, USA.
Sibley, D. A. (2014). The Sibley Guide to Birds, second edition. Alfred A. Knopf, New York, NY, USA.