All About

Vaux’s SwiftsThe Vaux’s Swift is a small migratory bird that travels long distances between wintering and breeding grounds. Its range lies along the west coast of North America, from Canada to Mexico and unlike most migrants who travel by night, the Vaux’s Swift moves during the day and then seeks a communal roosting spot to spend the night. Hollow snags within old growth forests were preferred but as old growth forests diminished, the swifts adapted. Today, large numbers of Vaux’s Swifts use industrial size chimney stacks to roost.

Little was known about this phenomenon until an effort to save the chimney at the former Frank Wagner Elementary School inMonroe, Washington launched an international effort tounderstand more about the migration habits of Vaux’s Swifts. Today, we recognize that specific chimneys have become essential roost habitats for these birds during migration.

wDescriptionThe Vaux’s Swift is the smallest of the four North American swifts measuring only 4 3/4 inches long with a wingspan of 12 inches. They are dusky black on top with grayish brown under parts and pale grey patches at the throat.

Swifts look and act much like swallows but are more closely related to hummingbirds. Like hummingbirds, swifts have very short forearms making their flight distinctive, stiff rapid beats that alternate with brief gliding movements.

Swifts rarely touch the ground or light on a branch, spending their entire day on the wing. Swifts have short legs with small claws. A reduced back toe makes it difficult for them to perch like other birds, but their powerful front toes and claws are perfectly suited for clinging to rough surfaces such as the inside of an old brick chimney.

And yes, a swift is swift! Fast enough to simply open their wide mouths and feast on insects by overtaking them in flight. An individual swift can consume up to 20,000 insects a day. They eat black flies, mosquitoes, stoneflies and whatever else is hatching, a role that highlights why this bird plays an important role in our ecosystem.

Field NotesThousands of Vaux’s swifts use the chimney at the Wagner Center as a communal roosting site during migration. These practiced aerialists use air currents to flock in circles, first clockwise, then counter clockwise, before dropping tail first into the chimney as the sun sets and the temperature cools.

Once inside the chimney, they overlap one another in “shingle” fashion to conserve body heat.

Swifts are often heard before they are seen, vocalizing with a non-stop, high-pitched twittering that becomes more pronounced as they gather in large flocks and never quiets…even through the night.

Fall migration is typically larger than spring migration. A pair of Vaux’s Swifts will spend most of the summer raising three to seven young who return with their parents on the trip south.

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WAGNER CENTER

Wagner Center (formerly Frank Wagner Elementary) has hosted one of the longest running Vaux’s Swift citizen science monitoring in the country. Since 2008 Larry Schwitters, project manager, has helped expand the effort to locate and document roost chimneys up and down the west coast. Over 200 volunteers have contributed by locating these rare, pre-World War II chimneys and faithfully counting the swifts coming to roost. You can find more information on the Vaux’s Happening website at www.vauxhappening.org.

Vaux’s Swifts are not endangered but they are listed as a Washington State species of concern. The loss of specific chimneys threatens their migration strategy.and raises questions about the stability of the species. Tax deductible donations are used to continue the research, preserve known roost sites along the entire length of the migration route, and explore roost site alternatives to maintain healthy populations of this important species.

Donations can be sent to:

Pilchuck Audubon Societyc/o Carolyn Lacy, Treasurer1429 Avenue D, PMB 198Snohomish, WA 98290