Setophaga townsendi

Setophaga townsendi, S. occidentalis, S. virens, and S. chrysoparia constitute a superspecies (Mengel 1964). Setophaga townsendi and S. occidentalis hybridize extensively in Washington, where S. townsendi appears to be expanding its range at the expense of S. occidentalis (Rohwer et al. 2001, Krosby and Rohwer 2009) (AOU 2011).

Formerly placed in the genus Dendroica. Phylogenetic analyses of sequences of mitochondrial and nuclear DNA (Lovette et al. 2010) indicate that all species formerly placed in Dendroica, one species formerly placed in Wilsonia (citrina), and two species formerly placed in Parula (americana and pitiayumi) form a clade with the single species traditionally placed in Setophaga (ruticilla). The generic name Setophaga has priority for this clade (AOU 2011).

Widespread in western North America, numerous, secure.

Breeding range extends from Alaska south through western Canada to U.S. Pacific Northwest and inland through parts of Idaho, Montana, and Wyoming (Stiles and Skutch 1989) Southern range extends west into the Cascades and interior ranges of Oregon and Washington, excluding the Central Basin (Wright et al. 1998). During the northern winter the species occurs in two distinct geographic areas: southwest British Columbia south along Pacific Coast to northern Baja California; and from southeastern Arizona and southwestern Texas through northwestern Mexico, south to highlands of Central America (Stiles and Skutch 1989, Wright et al. 1998).

This species is represented by a large number of occurrences.

The largest and most imminent threat is habitat loss on both wintering and breeding grounds (Reed 1991). This species is considered to be one of the long-distance migrants most likely to be negatively affected by alteration of tropical forest habitats because of its predominant use of mature coniferous and pine-oak forest habitats in Mexico and Central America (Vidal-Rodriquez 1992, Petit et al. 1995). These preferred montane habitats are undergoing rapid conversion to pasture land, corn and coffee plantations, and residential development (Wright et al. 1998).

Breeding populations may be susceptible to traditional timber-harvesting practices such as clear-cut logging and even-aged management (Wright et al. 1998). These methods typically result in the loss of habitat features that Townsend's are known to select (Spindler and Kessel 1980, Mannan and Meslow 1984, BPIF 1999). Timber harvest-associated habitat fragmentation increases exposure to edge-related predators and parasites, and it could potentially reduce breeding densities (Gates and Gysel 1978, Brittingham and Temple 1983, Andren and Angelstam 1988).

Predation and brood parasitism by brown-headed cowbirds are not known to pose significant threats.