Setophaga occidentalis

See Jackson et al. (1992) for aging criteria.

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).

Frequently found in association with yellow-rumped warbler (DENDROICA CORONATA).

Clutch size is 3-5. Nestlings are altricial and downy.