Are there chimney swifts in Washington state?

Introduction

Chimney swifts are small birds found throughout much of North America. They get their name from their habit of nesting and roosting primarily inside chimneys, contrary to their closest relative, the Vaux’s swift, which nests on vertical cliffs and canyon walls. Chimney swifts are migratory birds that breed in eastern North America and spend winters in South America. Their range extends as far west as western Texas. But do they reach as far west as Washington state?

Description and Identification of Chimney Swifts

Chimney swifts are tiny birds, measuring around 5.5 inches in length with a wingspan around 12 inches. They have short tails and very long, narrow, curved wings. Their plumage is a sooty gray-brown. The birds have stiff feathers on their tails that they use as props when perched vertically inside chimneys. Chimney swifts have tiny feet that are not well suited for perching. They can cling to rough vertical surfaces but do not often land voluntarily on the ground. In flight, chimney swifts exhibit a unique stiff-winged style of quick fluttering wingbeats interspersed with short glides. They are often described as resembling flying cigars.

Chimney swifts can be most easily confused with Vaux’s swifts. However, Vaux’s swifts have paler plumage, with a gray throat blending to brownish-gray underparts. Vaux’s swifts also have a slightly forked tail and lack the chimney swift’s stiff tail feather shafts used for clinging to vertical surfaces. In areas where their ranges overlap, chimney swifts tend to arrive earlier on breeding grounds than Vaux’s swifts.

Range and Distribution

Chimney swifts breed in eastern North America, from Nova Scotia and southern Quebec west to eastern Montana, Wyoming, and eastern Texas. Their winter range is in South America, including the Amazon basin. Chimney swifts migrate through much of the eastern half of the United States twice per year as they travel between their breeding and wintering grounds.

The western edge of the chimney swift’s breeding range appears to roughly follow the 100th meridian. This longitudinal dividing line separates the more humid eastern part of the continent from the drier Great Plains and western regions. It is likely that this gradient in average precipitation, humidity, and availability of suitable nesting and roosting sites delineates the chimney swift’s range limit.

Range Limits in Western States

Along their western range edge, chimney swifts breed in eastern parts of the following states:

• Texas – Breeds in eastern half of state, west to around Abilene and San Angelo
• Oklahoma – Breeds in eastern half of state, west to around Oklahoma City
• Kansas – Breeds across state except for the High Plains in western Kansas
• Nebraska – Breeds in eastern third of state
• South Dakota – Rare and local summer resident in southeastern corner
• North Dakota – No breeding records
• Wyoming – Very rare summer records in the east
• Montana – Rare and local summer resident in far northeastern corner

There are no breeding records for chimney swifts in states west of eastern Montana, including Washington state. The 100th meridian corridor appears to mark the western limit of their normal breeding distribution.

Rare and Accidental Records West of Breeding Range

There have been a small number of rare and accidental records of individual chimney swifts observed west of their normal breeding range:

• Idaho – Fewer than 5 records
• Utah – 1 record in 1880s, 2 records in late 1900s
• Oregon – About 10 records
• California – Around 25 records, mostly since 1950
• Nevada – 2 records
• Colorado – Around 15 records, mostly since 1990

Nearly all of these exceptional sightings have been in spring, typically in May or June. This indicates they were likely migrants overshooting their target destinations. There are no accepted breeding records for chimney swifts in any western states beyond eastern Montana and Wyoming.

No Records of Chimney Swifts Breeding in Washington

Within the available literature, there are no confirmed breeding records of chimney swifts anywhere in Washington state. All sightings have consisted of one or two individuals observed during migration periods, rather unusually far outside the species’ expected migration corridors and winter range.

Notable accidental reports of chimney swifts in Washington include:

• May 1888 – 1 bird in Franklin County along the Snake River
• May 1960 – 1 bird in Okanogan County in north-central WA
• May 1981 – 1 bird in Kittitas County in central WA
• September 1990 – 1 bird southwest of Seattle
• October 1999 – 1 bird in Pacific County in southwest WA

The Washington Department of Fish and Wildlife does not include chimney swifts on their list of breeding bird species for the state. All major bird field guides describe the chimney swift range as stopping well short of Washington. There are simply no records indicating successful breeding by chimney swifts anywhere in Washington, despite a handful of rare migratory observations over the past century and a half.

Habitat Limitations in Washington

One factor that likely precludes chimney swifts from breeding in Washington is a relative scarcity of suitable nesting and roosting sites. Chimney swifts require open chimneys made of brick, rock, or mortared hollow blocks where they can gain access inside. Chimneys faced with wood, metal, or tightly spaced rebar typically do not allow access. Chimney swift populations have declined in parts of their core range due to chimneys being capped for safety reasons and scarceness of large hollow trees.

In Washington, most areas simply lack sufficient numbers of suitable chimneys for nesting. Brick and mortared masonry chimneys are rare in the Pacific Northwest compared to many parts of the chimney swift’s main range. The predominance of wood stoves over open fireplaces also reduces roosting options. Washington’s relatively mild climate means fewer large, unlined chimneys suitable for nesting. The scarcity of suitable chimney structures is likely a key factor preventing chimney swifts from colonizing the state.

Lack of Nearby Breeding Populations

Another obstacle to chimney swifts occupying Washington is the considerable distance from their core breeding range. The nearest area harboring breeding chimney swift populations is likely southeast Montana, over 500 miles away. While individual swifts have proven capable of long migrations and overshooting migration endpoints, it is unlikely that a sustainable breeding colony could be founded from such distant source regions. Successful colonization requires consistent annual arrival of multiple birds. With the immense distance to occupied areas, vagrants would be unlikely to find mates or sufficient resources. This isolation from extant breeding populations creates a secondary barrier beyond just habitat limitations.

Climate and Geography

Other aspects of Washington’s setting also likely play a role. The state has a predominately marine west coast climate. It lies well west of the 100th meridian line that seems to delineate the chimney swift breeding distribution. The Cascade Range creates drier conditions in eastern parts of the state. Washington is also positioned far north of the chimney swift’s core range. The species may simply be limited by aspects of the regional climate and geography that differ substantially from its historic breeding range in the eastern half of the continent.

Conclusion

In summary, while migrating chimney swifts have turned up rarely and accidentally in Washington over the years, there is no evidence that they have ever successfully nested or bred anywhere in the state. A lack of large, suitable masonry chimney structures probably serves as the primary barrier. Additionally, Washington lies distantly isolated from the nearest breeding populations, while also possessing a substantially different climate and geography from the chimney swift’s historic range. Taken together, these multiple factors indicate that Washington state falls well outside of the expected range for breeding chimney swifts. The species should be considered at best an exceptionally rare vagrant in Washington, rather than a regular member of the avian community. While the appearance of a migrant chimney swift could not be ruled out, it would not signal successful colonization or local nesting.

References

Here are some references used in researching this article: