With spring upon us, the attention of birders turns to finding warblers. These are the birds that Roger Tory Peterson called “the butterflies of the bird world.” Over 50 species of warblers are making their migrations of thousands of miles from the tropics of Central and South America to North America. The largest and most varied warbler migrations occur in eastern North America but once they reach the boreal forest, millions of them continue to the western reaches of the forest. The Pacific Northwest region supports a group of twelve warbler species and in April and May they arrive in Washington. To reach the northwest these warblers followed a flyway along the Pacific coast and western slope of the Cascade Range.
Four of the warblers found in Washington are west coast specialties. Black-throated Gray, MacGillivray’s, Townsend’s, and Hermit Warblers are found only west of the Rocky Mountains. Knowing when and where to look for them is key to seeing these bird gems and learning more about the status and distribution of them helps us locate them.
The chart below shows when to expect each of these warbler species in our region. The arrival and departure columns give you the best window for spotting each bird. The breeding area notes tell you each species’ favored habitat. Some are more likely west of the Cascades and others east of the mountains, and a few occupy specific elevation ranges or habitat types.
Members of all twelve of these warbler species breed in Washington, but the majority of them will pass through the state and find suitable habitats in the boreal forest or coastal regions of Canada and Alaska. In spring these birds will be the most active. They will sing more as they look for a mate and stake out a territory.
| Wood-Warbler | Breeding Area | Arrival | Departure |
|---|---|---|---|
| Northern Waterthrush (Parkesia noveboracensis) | East of Cascades and Okanogan Valley in British Columbia and Washington | Mid-April to mid-May | Late August |
| Lutescens – Pacific slope Orestera – interior mountains |
Late March to April April to May |
October August to October |
|
| Nashville Warbler (Leiothlypis ruficapilla) | Common low- to mid-elevation breeder in eastern BC and WA | Mid-April to May | August to September |
| Black-throated Gray Warbler (Setophaga nigrescens) | Common west of Cascades and Coast Range; uncommon east of crest in Oregon | April 12-19 | Late September |
| Townsend's Warbler (Setophaga townsendi) | Conifer-forest zones from BC south; hybridizes with Hermit Warbler | Late April | Mid- to late August |
| Hermit Warbler (Setophaga occidentalis) | Common in OR, uncommon in WA north to Olympic Mountains | Late April to early May (WA) | Mid-June to late July |
| Yellow-rumped Warbler (Setophaga coronata) | Auduboni – common Coronata (Myrtle) – Rockies |
Mid-April to May | Mid-September to October |
| Northern Yellow Warbler (Setophaga petechia) | Low- to mid-elevation breeder in Pacific Northwest | Mid-April | July |
| American Redstart (Setophaga ruticilla) | Uncommon; low- to mid-elevation breeder east of Cascades, local in Skeena region (BC) and Skagit Valley (WA) | Late May | Early to mid-September |
| Wilson's Warbler (Cardellina pusilla) | Chryseola – westside breeder Pileolata – interior BC |
April, peak May May to June |
Mid-September Late August to September |
| MacGillivray's Warbler (Geothlypis tolmiei) | Common sea level to tree line | Late April to May | Mid-September |
| Common Yellowthroat (Geothlypis trichas) | Common low- to mid-elevation breeder | Late March to early May | August to early October, rare after November |