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BC Conservation Data Centre: Species Summary


Setophaga occidentalis
Hermit Warbler

 
Scientific Name: Setophaga occidentalis (Townsend, 1837)
Scientific Name Synonyms: Dendroica occidentalis
English Name: Hermit Warbler
 
Classification / Taxonomy
Scientific Name - Concept Reference: American Ornithologists' Union (AOU). 1998. Check-list of North American birds. Seventh edition. American Ornithologists' Union, Washington, D.C. [as modified by subsequent supplements and corrections published in The Auk]. Also available online: http://www.aou.org/.
Classification Level: Species
Taxonomy Comments: The change from genus name Dendroica to Setophaga was based on:
Chesser, R.T. et.al. 2011. Fifty-second Supplement to the American Ornithologists' Union Checklist of North American Birds. The Auk 128(3):600-613.
Species Group: Vertebrate Animal
Species Code: B-HEWA
Kingdom Phylum Class Order Family
Animalia Craniata Aves Passeriformes Parulidae
   
Conservation Status / Legal Designation
Global Status: G4G5 (Apr 2016)
Provincial Status: SNA (Apr 2024)
BC List: Accidental
Provincial FRPA list:   
Provincial Wildlife Act:
COSEWIC Status:
SARA Schedule:
General Status Canada: 8 - Accidental (2005)
Migratory Bird Convention Act: Y
   
Ecology & Life History
General Description: See Jackson et al. (1992) for aging criteria.
Global Reproduction Comments: Clutch size is 3-5. Nestlings are altricial and downy.
Global Ecology Comments: Frequently found in association with yellow-rumped warbler (DENDROICA CORONATA).
Migration Characteristics:
(Global / Provincial)		 
    Nonmigrant:
    Local Migrant:
    Distant Migrant:
    Within Borders Migrant: 		N /
Y /
Y /
na /
Global Migration Comments: On lower Colorado River Valley, Arizona, transient in late-April to late May, and mid-August to mid-October (Rosenberg et al. 1991). Winter in highlands from central Mexico into Central America to northern Nicaragua; accidental in western Panama, often occurs with Townsend's warbler (DENDROICA TOWNSENDI) (Ehrlich et al. 1988; Stiles and Skutch 1989; Howell and Webb 1995).
Habitats:
(Type / Subtype / Dependence)
Global Habitat Comments: BREEDING: Generally in upland coniferous forests with high canopy volume; shrub understories less important (Pearson 1997, AOU 1998). Prefers mature stands of pine and fir, with large trees and dense cover; prefers scattered groups of tall trees emergent from canopy (USDA Forest Service 1994). Douglas-fir (PSEUDOSTUGA MENZIESII) an important tree species throughout breeding habitat. Nests in older second-growth (> 40 yrs) and mature forests (> 120 yrs; Meslow and Wight 1975).

In Washington and Oregon, found in Douglas-fir, western hemlock (TSUGA HETEROPHYLLA), Pacific silver fir (ABIES AMABILIS) and other firs (ABIES spp.). Also occurs in low densities in subalpine forests dominated by subalpine-fir (ABIES LASIOCARPA), which may include lodgepole pine (PINUS CONTORTA) and other conifers (Manuwal et al. 1987). In northwest Washington east of Puget Sound, once bred in oak-fir associations, but habitat is vanishing. In southern Washington Cascades Douglas-fir forests, found most abundant in young (55-80 year; average 7.9 birds per visit); relatively dry old-growth (210-440 year; 6.2 birds per visit); and mature (95-190 year; 5.6 birds per visit) stands; less abundant in wet (300-730 year; 1.6 birds per visit) and mesic (250-700 year; 2.1 birds per visit) old-growth stands (Manuwal 1991).

In Coastal Oregon Douglas-fir forests, was one of most commonly detected species, but was more abundant in young stands (40-72 year; two-year average 69.6 pairs per 40 hectares) than in mature (80-120 year; 41.1 pairs per 40 hectares) or old-growth stands (200-525 year; 48.4 pairs per 40 hectares), where canopy cover decreased with stand age (Carey et al. 1991). Positively associated with percent conifer cover, larger trees and taller trees; negatively associated with deciduous tree and shrub understory (Morrison 1982). In a comparison of streamside to upslope sites in mixed-coniferous forests dominated by Douglas-fir, was never detected in riparian sites (McGarigal and McComb 1992).

In Oregon Cascades, was most frequently detected species in young (30-80 year) and mature (80-200 year) Douglas-fir stands, and was second-most frequently detected species in old-growth stands (200-500 year; Gilbert and Allwine 1991). A synthesis of studies in Oregon Cascades Douglas-fir/western hemlock forests, showed the species most abundant in natural old-growth (200-450 yr), natural mature (80-190 year) and young closed canopy plantation (30-60 year) stands, and absent in clearcut and retention-cut plots (clearcuts with 2-14 trees per hectare or 1-6 trees per acre retained; Hansen et al. 1995).

In coastal California, breeds in Douglas-fir and coast redwood (SEQUOIA SEMPERVIRENS) habitats (Dunn and Garret 1997); in Douglas-fir forests found most abundant in older, cooler, and higher-elevation stands, and counts were highest in stands >300 years (Raphael 1987). In Marin County, occurs in moderately dense Douglas-fir and douglas-fir/coast redwood forests in canyons at mid- to high elevations with east or north exposures (Shuford 1993, cited in Pearson 1997). In California mountains, found in red fir (ABIES MAGNIFICA), white fir (ABIES CONCOLOR), sugar pine (PINUS LAMBERTIANA), ponderosa pine (PINUS PONDEROSA), Jeffrey pine (PINUS JEFFREYI), lodgepole pine, and sequoia (SEQUOIA GIGANTEA) forests (Verner and Larson 1989, Dunn and Garrett 1997). In a mixed conifer-oak forest, showed a preference for foraging in ponderosa and sugar pine (Airola and Barrett 1985).

Usually nests on outer limb of conifer, 6-18 meters above ground (sometimes 0.6-15 meters high).

NONBREEDING: In a variety of habitats during migration including woodland and scrub habitats composed of live oaks (QUERCUS spp.), cottonwood (POPULUS spp.), tamarisk (TAMARIX spp.), chaparral, desert woodlands, cottonwood-willow, large mesquite, and pecan orchards (Rosenberg et al. 1991, Dunn and Garrett 1997). Winters in conifers, especially pines and pine-oak habitats from 1,500 to 3,000 meters (Howell and Webb 1995, Dunn and Garrett 1997, AOU 1998). In Mexico, Hutto (1992) describes this species as a two-zone generalist, using both cloud forest and pine-oak-fir forest. In Costa Rica mostly in hedgerows or at forest edge, forages in conifers, especially Guatemalan cypress (CUPRESSUS LUSITANICA) (Stiles and Skutch 1989).
Food Habits: Invertivore: Adult, Immature
Global Food Habits Comments: Forages actively in branches of conifers for insects (e.g., beetles, caterpillars, flies, etc.) and spiders. Often forages high in trees, 30-60 meters above ground (Terres 1980). In Sierra-Nevada mixed conifer, foraged 5 to 25 meters above ground (Airola and Barrett 1985), and in Giant Sequoia forest foraged above 10 meters (Kilgore 1971).
Global Phenology: Diurnal: Adult, Immature
Provincial Phenology:
(1st half of month/
2nd half of month)
Colonial Breeder: N
Length(cm)/width(cm)/Weight(g): 14/ / 10
Elevation (m) (min / max): Global: 
Provincial: 
   
 
Distribution
Endemic: N
Global Range Comment: BREEDING: southwestern Washington south through mountains to southern California and west-central Nevada. Populations fragmented within range (AOU 1983, Pearson 1997). NON-BREEDING: primarily from Durango and southern Nuevo Leon south to Oaxaca, from Chiapas to Guatemala, and southern Honduras to western Nicaragua (Pearson 1997). Rare and/or local in coastal California (from central California south) and in west-central Nicaragua and Costa Rica; accidental to western Panama (AOU 1983, Stiles and Skutch 1989, Pearson 1997). Highest densities in Central Volcanic Belt of Mexico (Howell and Webb 1995). MIGRATION: through Sonora, Chihuahua, San Luis Potosi, and rarely northern Baja California.
 
Authors / Contributors
Global Information Author: Hammerson, G.
Last Updated: Mar 21, 1994
Provincial Information Author:
Last Updated:
   
References and Related Literature
American Ornithologists' Union (AOU). 1983. Check-list of North American Birds, 6th edition. Allen Press, Inc., Lawrence, Kansas. 877 pp.
American Ornithologists' Union (AOU). 1998. Check-list of North American birds. Seventh edition. American Ornithologists' Union, Washington, D.C. [as modified by subsequent supplements and corrections published in The Auk]. Also available online: http://www.aou.org/.
Bent, A. C. 1953. Life histories of North American wood warblers. U.S. Natl. Mus. Bull. 203. Washington, D.C.
Carter, M., C. Hunter, D. Pashley, and D. Petit. 1998. The Watch List. Bird Conservation, Summer 1998:10.
Carter, M., G. Fenwick, C. Hunter, D. Pashley, D. Petit, J. Price, and J. Trapp. 1996. Watchlist 1996: For the future. Field Notes 50(3):238-240.
Griscom, L., and A. Sprunt, Jr. 1979. The warblers of America. Doubleday and Co., Garden City, New York. 302 pp.
Harrison, C. 1978. A Field Guide to the Nests, Eggs and Nestlings of North American Birds. Collins, Cleveland, Ohio.
Harrison, H.H. 1984. Wood warblers' world. Simon and Schuster, New York. 335 pp.
Jackson, W.M., C.S. Wood, and S.S. Rohwer. 1992. Age-specific plumage characters and annual molt schedules of Hermit Warblers and Townsend's Warblers. Condor 94:490-501.
National Geographic Society (NGS). 1983. Field guide to the birds of North America. National Geographic Society, Washington, DC.
Pearson, S. F., and D. A. Manuwal. 2000. Influence of niche overlap and territoriality on hybridization between Hermit Warblers and Townsend's Warblers. Auk 117:175-183.
Rohwer, S., and C. Wood. 1998. Three hybrid zones between Hermit and Townsend's Warblers in Washington and Oregon. Auk 115(2):284-310.
Stiles, F. G. and A. F. Skutch. 1989. A guide to the birds of Costa Rica. Cornell University Press, Ithaca, New York, USA. 511 pp.
Terres, J. K. 1980. The Audubon Society encyclopedia of North American birds. Alfred A. Knopf, New York.
 

Please visit the website Conservation Status Ranks for definitions of the data fields used in this summary report.

Suggested Citation:

B.C. Conservation Data Centre. 1994. Species Summary: Setophaga occidentalis. B.C. Minist. of Environment. Available: https://a100.gov.bc.ca/pub/eswp/ (accessed Jun 4, 2026).