Yellow-Breasted Chat (Icteria Virens)

Aves (Birds): Passeriformes, Parulidae Yellow-breasted Chat (Icteria virens) Potential Occurrence: Nesting Unlikely to Occur

Status: (Nesting)

Federal: None

State: SSC

Other: G5 S3

Species Description: The largest of the wood Photo: Jim Conrad warblers, the Yellow-breasted Chat is 7.5 inches long and has a 10 inch wingspan (Sibley 2000). Compared to other warblers, this bird has a large bill and long tail. Olive-brown upper parts and white underparts, with the distinct yellow patch along the chin, throat, and breast (Eckerle 2001). There are white “spectacles” around the eyes (Sibley 2000).

Distribution: Breeds in northwestern North America from British Columbia through California, and has a widespread range in the eastern United States and winters in Mexico from Baja Calfornia to northern Sinaloa (Hammerson 1996). It is rare or absent in 35% of its historic breeding range in much of the California’s Central Valley. In northwestern California, Yellow- breasted Chats are widely distributed and are regularly reported on BBS routes in Humboldt, SIskyou, Shasta, Mendocino, and Lake Counties (Shuford 2008).

Life History & Threats: The Yellow-breasted chat constructs a nest close to the ground (from ground level to 2 meters) and lays between 3-5 eggs from mid-May to late June (Hammerson 1996). Only the female incubates the eggs and broods the nestlings, but both parents feed the young (Eckerle 2001). Nestlings fledge in 8-11 days after hatching.

Chats’ dependence on understory and shrubby riparian vegetation for nesting makes them vulnerable to habitat loss from vegetation removal along river channels during flood-control maintenance and from urban and agricultural development. (From Shuford 2008)

Brown-headed cowbird is a brood parasite of this species (Eckerle 2001).

Habitat & Habitat Associations:

Nesting Habitat: The Yellow-breasted chat nests in dense shrubs along riparian corridors and in early-successional open canopy forest (i.e. after a clear cut) (Eckerle 2001; Schuford 2008).

Chats will nest in tamarisk, Himalayan Blackberry (Rubus discolor), Russian Olive (Elaeagnus angustifolius), and other non-native plants that provide dense shrub layers. (From Schuford 2008)

Conceptual Basis for GIS Model Development: We mapped potential habitat of the Yellow- breasted Chat as riparian vegetation. GIS vegetation layers did not show willow and alder as occurring along Rancheria Creek, but field reconnaissance indicated that many small patches and thin corridors of this vegetation type occur on the banks of the Creek. To capture the occurrence of this habitat types, we mapped riparian vegetation as a 130-m buffer along the main stem of Rancheria Creek. Riparian woodland, forest and scrub are disjunct within this area.

Note that small patches of Cottonwood Woodlands do occur immediately north of the Study Area along Rancheria Creek, but do not occur within the map view.

Potential Occurrence in the Galbreath Wildlands Preserve: Protection status for this species applies to nesting individuals.

Habitat: Yellow-breasted Chats nest in dense shrubs along riparian corridors. Nesting habitat is poor to moderate quality in the Preserve (Figure 92). Riparian scrub and woodlands with willows do occur within the area, but are fragmented and poorly developed due to regular flooding. Riparian vegetation shown in Figure 92, is an estimate of a zone containing only a patchy distribution of riparian woodland and scrub. It is uncertain whether any areas of riparian vegetation are large and dense enough to provide adequate nesting habitat for Yellow-breasted Chats.

Nearest Occurrence:

Documented Occurrences in the Galbreath Wildlands Preserve: This species has not been documented on the Preserve. To our knowledge no surveys have been conducted.

Nearest Occurrence to the Galbreath Wildlands Preserve: This species has not been reported to occur in USGS quads adjacent to the Preserve.

Summary: Nesting Yellow-breasted Chats are “Unlikely to Occur” on the Preserve because potential nesting habitat is highly fragmented and may not be extensive enough to support breeding individuals.

References

Eckerle KP, Thompson CF. 2001. Yellow-breasted Chat (Icteria virens), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; . Accessed 2010 Jul 19.

Hammerson G, Dirrigl F, Thompson CF. 1996 Feb 16. Comprehensive Report Species- Icteria virens. NatureServe Explorer. Version 7.2. . Accessed 2010 Jul 18.

Shuford WD, Gardali T, eds. 2008. California Bird Species of Special Concern: A ranked assessment of species, subspecies, and distinct populations of birds of immediate conservation concern in California. Studies of Western Birds 1. Western Field Ornithologists, Camarillo, California, and California Department of Fish and Game, Sacramento.

Sibley DA. 2000. The Sibley Guide to Birds. New York: Alfred A Knopf. p 457.

Species Account Description: Kandis Gilmore & Emily Harvey