Orange-crowned Warbler Life History

Habitat

Look for Orange-crowned Warblers in shrubs and low-growing vegetation in riparian settings, patches of forest, and chaparral. This widespread species breeds in an impressive range of habitat types, from alders and willows scattered amongst stands of old-growth temperate rainforest in coastal Alaska, to fir-aspen woodlands up to 7,500 feet in central Arizona. In the northern Rockies Orange-crowned Warblers breed in open or logged forest, including clearcuts. Overall, they breed in more forest types than nearly any other warbler species. During breeding season in Washington they occur in willow, alder, and maple thickets along with brushy cover growing in old burns and second growth forest. Oregon breeders are common in the open canopy woodlands dominated by Oregon white oak and are less often seen in denser Douglas-fir forest. Central California breeders seek sites where California laurel, coast live oak, and madrone dominate. Birds breeding on the Channel Islands nest in plant communities of torrey pine, chaparral, and coastal bluff and sage scrub. Wintering Orange-crowned Warblers seek out habitat with structure similar to their breeding grounds, including oak woodland and mixed chaparral habitat in southern California, pine-oak forests in Mexico, and brushy woodlands and second growth in the Caribbean.Back to top

Food

Orange-crowned Warblers eat mainly invertebrate prey, including ants, beetles, spiders, flies, and caterpillars. Look for Orange-crowned Warblers from the ground to the treetops as they poke, clamber, and flit through vegetation. They supplement their insect diet with fruit, berries, seeds, and plant galls, and are common visitors at the sapwells drilled by sapsuckers and some other woodpeckers. These warblers also pierce the base of flowers to get at the nectar. In winter Orange-crowned Warblers can be attracted to backyard feeders offering suet and peanut butter, and they sometimes appear at hummingbird feeders. Back to top

Nesting

Nest Placement

Female Orange-crowned Warblers choose nest sites by fluttering through low vegetation, eventually choosing a site on or near the ground. Nest sites include shady hillsides, steep road or trail cuts, the bases of snowmelt drainages, and gullies or canyons, often sheltered by vegetation. Nests may be built on moss, in rock cracks or depressions in the soil, or on the ground directly below woody plants or nestled in fern fronds. Orange-crowned Warblers in the Channel Islands are the only subspecies to consistently build their nest off the ground, placing them in low shrubs and up to 20 feet high in toyon, coast live oak, and ironwood trees.

Nest Description

The female builds the nest, taking up to 4 days to form an open cup nearly 4 inches across and 2.5 inches high. She first lays down a foundation of dead leaves, stems, and other coarse plant material, then weaves an outer layer that can be made up of leaves, coarse grass, fine twigs, bark, wood, moss, and sheep wool. She lines the nest cup with finer grasses, and animal hair from small mammals and sometimes elk or horses.

Nesting Facts

Behavior

Orange-crowned Warblers flit rapidly through shrubs, trees, vine tangles, and other vegetation as they glean insects from leaves and buds. They usually feed from perches but sometimes sally like a flycatcher to snag a flying insect or hover to reach the undersides of leaves. These wood warblers also poke through leaf litter and probe bark and moss with their sharp, fine-tipped bills in search of hidden prey. In late winter and spring, males sing as they establish territories to attract a mate, then enter a silent stage as courtship begins. A courting male may follow a potential partner through the undergrowth of his territory and may mimic a soliciting female by drooping his wings, spreading his tail, and pointing his bill skyward. Once the pair is established and the female has built the nest the male begins to sing again. During territorial displays or when threatened, males raise their crown feathers to flash a vivid orange patch. Male Orange-crowned Warblers can spend hours chasing off a conspecific male, but will tolerate other species nesting close by, including Song Sparrows, Wilson’s Warblers, and MacGillivray’s Warblers. Orange-crowned Warblers mix with other warbler species, juncos, chickadees, kinglets, and vireos during migration and on the wintering grounds.

Conservation

Orange-crowned Warblers are abundant in some parts of their breeding range, but overall, populations declined by approximately 28% between 1966 and 2019, according to the North American Breeding Bird Survey. Declines have been steeper in the U.S., where populations fell by 54% during that time. Partners in Flight estimates the global breeding population at 82 million and rates them 9 out of 20 on the Conservation Concern Score, indicating a species of low conservation concern. Overall, Orange-crowned Warbler probably benefit from logging practices that open up forest canopies and create dense shrub growth. However, practices that damage shrub layers can reduce habitat suitability for the species. Examples include some logging practices in coastal Alaska, and cattle grazing in California oak woodlands. Preserving wooded stream corridors in the West would be an important step to preserve appropriate habitat for migrating warblers. Other causes of Orange-crowned Warbler mortality include collisions with airport towers, TV towers and wind turbines.

Credits

Gilbert, William M., Mark K. Sogge and C. Van Riper III. (2010). Orange-crowned Warbler (Oreothlypis celata), version 2.0. In The Birds of North America (P. G. Rodewald, editor). Cornell Lab of Ornithology, Ithaca, New York, USA.

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.

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.

Stephenson, T. and S. Whittle (2013). The Warbler Guide. Princeton University Press, New Jersey, USA.

Back to top