Living Bird Magazine
Vaux's SwiftChaetura vauxi
- ORDER: Caprimulgiformes
- FAMILY: Apodidae
An aerialist of western forests, Vaux’s Swift is a dark, tiny-bodied, narrow-winged bird much like the Chimney Swift of the eastern U.S. They spend most of the day in the air, taking small insects and spiders in rapid, twisting flight. They roost and even nest communally in hollow trees in mature evergreen forests (less often in chimneys). Adults construct a nest of twigs, cemented with their saliva to the inside of a tree cavity, and roost near the nest, clinging vertically to the side of the cavity.More ID Info
Find This Bird
To find a swift, look to the sky. For Vaux’s Swifts, try scanning above the treetops, especially of mature coniferous forests—and be sure to look in summer since this species spends winters in Central and South America. Other places to look include areas rich in flying insects, including forest openings, edges of waterways, and over burned areas. Check your local bird club for “swift watches” that may happen in September, as flocks of Vaux’s Swifts gather to roost, often in chimneys, prior to their main southward migration.
- Vencejo de Vaux (Spanish)
- Martinet de Vaux (French)
- Cool Facts
- Vaux's Swift is the smallest swift in North America.
- Vaux's Swifts roost communally, by the hundreds or sometimes the thousands, presumably to conserve heat. They let their body temperature drop and become torpid on cold nights, reviving in the warmth of day. This species and the unrelated Pygmy Nuthatch are the only species in North America that combine these three techniques (sheltering, huddling, and torpor) to survive the cold.
- Vaux's Swifts descend into their roost tree essentially at once, spiraling down in a very dramatic rush at nightfall. As many as 35,000 may roost in the same site!
- Vaux's Swift is named for William S. Vaux, a member of the Academy of Natural Sciences and a friend of John K. Townsend, who first described the species. The name looks like it might be pronounced voh but Vaux himself pronounced it vawks.
- The oldest recorded Vaux's Swift was at least 5 years, 1 month old when it was recaptured and rereleased during banding operations in Venezuela.
- To feed their young, adult Vaux’s Swifts may make 50 trips to the nest each day, beginning at dawn and ending at dusk. Each parent feeds the nestlings a ball of about 115 insects per visit. That means a single pair of swifts may remove about 11,500 insects per day from the air!