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Status: Population size: 2.4 million Photo by Bob Steele.

Hermit Warbler
(Dendroica occidentalis)

Despite their striking yellow, black, and white plumage, Hermit Warblers are often difficult to see, as they forage high above the forest floor in the canopy of coniferous forest. Although population trends for this species appear to be stable, Hermit Warblers are considered a conservation priority because of their habitat specialization, their limited breeding range in California, Oregon, and Washington, and the continued threat of large-scale logging in that area.

Identification
On their western North American breeding grounds, adult male Hermit Warblers are easily identified by the combination of their bright yellow faces, black throats, and white underparts. Males also show two white wing bars on their blue-gray wings. Female Hermit Warblers are slightly duller than males, have less black on their throats, and have less distinct wing bars.

Distribution and Population Trends
Hermit Warblers have a relatively limited breeding range confined to the Coast, and the Cascade and Sierra Nevada mountain ranges of Washington, Oregon, and California. This species can be found nesting at the A?o Nuevo/Big Basin Important Bird Area in California. Some Hermit Warblers winter along the coast of central and southern California, but this species winters primarily in the mountains of western Mexico, south to Guatemala, Honduras, and Nicaragua.

Breeding Bird Survey data from 1966 to 2000 show a small, non-significant increase of 0.30% per year for Hermit Warblers.

Ecology
On their breeding grounds, Hermit Warblers are birds of coniferous forests; they prefer cool, wet fir forests at elevation, and moist forests of Douglas-fir, hemlock, and western redcedar closer to sea level. These birds often forage near the tops of massive trees, sometimes at heights of up to 200 feet. Hermit Warblers also nest at relatively high heights, with females building nests on branches anywhere from 20 to 120 feet above the ground. Because of the height of Hermit Warbler nests, nesting behavior of this species is not well known; it is believed that both sexes incubate a clutch of four to five eggs, probably for about 12 days. Females (and possibly males) feed the nestlings for about eight to ten days before the young birds leave the nest. Hermit Warblers employ a number of different foraging techniques, including sallying, hover-gleaning, and gleaning from a perch, to catch spiders, caterpillars, beetles, and other invertebrates. On this species' major wintering grounds in Central America, Hermit Warblers are found in montane pine-oak or pine forests, where they forage in mixed-species flocks.

Hermit Warblers hybridize with their close relatives, Townsend's Warblers, where their ranges overlap along the Cascade Crest in Oregon and north of the Columbia River in Washington. It also appears that Townsend's Warblers are outcompeting and replacing Hermit Warblers across a considerable part of Hermit Warbler's breeding range.

Threats
The major threat to this species appears to be the degradation or destruction of breeding habitat. Hermit Warblers are habitat specialists, breeding only in coniferous forests with a well-developed canopy. In managed forests in Washington, Hermit Warblers are found in highest numbers in stands that are more than 30 years old, and are not found at all in conifer stands that are less than 20 years of age. As habitat specialists with a limited breeding range, Hermit Warblers could certainly be threatened by future logging (especially clearcutting) in the Pacific Northwest.

Conservation
The California Partners in Flight Coniferous Forest Bird Conservation Plan (http://www.prbo.org/calpif/htmldocs/conifer.html) contains management recommendations for conserving California's coniferous bird communities. Two recommendations in this plan were specifically mentioned as being beneficial to important Hermit Warbler populations in the Sierra Nevada: managing forests for closed canopy and managing for tree species diversity.

What Can You Do?
Audubon and our partners in conservation coordinated the submission of over two million comments to the U.S. Forest Service in support of the Roadless Area Conservation Rule, which would protect habitat for Hermit Warblers and many other species. Unfortunately, implementation of the Rule has been stalled and attempts are being made to weaken it. To help in protecting these vital habitats visit: http://www.audubon.org/campaign/latestnews.html#roadless.

Audubon's Important Bird Area program is a vital tool for the conservation of Hermit Warblers as well as other species. To learn more about the Important Bird Areas program and how you can help, visit: http://www.audubon.org/bird/iba/.

CIPAMEX, Audubon's BirdLife International partner in Mexico, has an Important Bird Areas program that is working to protect wintering habitat for Hermit Warbler and many other species. To learn more about Mexico's Important Bird Areas program and how you can help visit: http://132.248.79.80/wwwcampus/cipamex/

Information on where Hermit Warblers occur and in what numbers is vital to conserving the species. Help in monitoring this and other species by reporting your sightings to eBird. A project of Audubon and the Cornell Lab of Ornithology, eBird is the world's first comprehensive on-line bird monitoring program: http://www.audubon.org/bird/ebird/index.html.

References
CalPIF (California Partners in Flight). 2002. Version 1.0. The draft coniferous forest bird conservation plan: a strategy for protecting and managing coniferous forest habitats and associated birds in California (J. Robinson and J. Alexander, lead authors). Point Reyes Bird Observatory, Stinson Beach, CA. http://www.prbo.org/calpif/plans.html.

Dunn, J., and K. Garrett. 1997. Peterson Field Guide: Warblers. Houghton Mifflin Company, New York.

Kaufman, Kenn. 1996. Lives of North American Birds. Houghton Mifflin Company, New York.

Pearson, S. F. 1997. Hermit Warbler (Dendroica occidentalis). In The Birds of North America, No. 303 (A. Poole and F. Gill, eds.). The Academy of Natural Sciences, Philadelphia, PA, and The American Ornithologists' Union, Washington, D. C.