Natural History

Vaux’s Swifts look like small, dark, fast-flying cigars with wings. Their small bodies are 4-5 inches in length. Their wings are crescent-shaped and beat with swift, rapid, bat-like movements. Swifts do not “perch,” and are found flying or clinging to vertical surfaces such as trees and chimneys.

Vaux’s Swifts are truly amazing aerialists. They spend much of the time in the air and forage, drink, court, collect nesting materials, and copulate all in flight. They have a voracious appetite for flying insects and ballooning spiders.

Vaux’s Swifts at Chapman Elementary School, Scott Carpenter

Vaux’s Swifts arrive in Oregon in late April, court their mates in May and June, and have their 4-6 eggs laid and hatched by July. In the fall, swifts congregate in large groups as they prepare for their migration southward to Central America and Venezuela. During September, large groups of swifts pass through the Portland-Vancouver metropolitan region.

It is not uncommon for these migrating swifts to use chimneys to roost in during the night, and once a population of swifts locates an appropriate chimney, they are likely to return year after year. Groups of roosting swifts can range in size from just a few individuals to as many as 35,000 in some larger smokestacks.

Chapman Elementary School in northwest Portland houses one of the largest known roosts of migrating Vaux’s Swifts in the world. Typically the swifts will only stay a couple of weeks before continuing their migratory journey.

What’s in a Name?

The Vaux’s Swift is named for William Sansom Vaux (1811 – 1882), an American mineralogist. Vaux was the friend of John Kirk Townsend, a noted ornithologist of the day and the person to discover the Vaux’s Swift for science. Since a scientist cannot name a species for him/herself, it had long been common practice to name a new species and commemorate an admired friend at the same time.

Vaux (pronounced VOX) was born in Philadelphia. He became a member of the Academy of Natural Sciences in 1834, and served it in various capacities in the next forty-eight years, including vice-president. He was also a member of the Zoological Society of Philadelphia and one of the original members of the American Association for the Advancement of Science.

He made several trips to Europe to collect mineral specimens, and by his death his collection was considered to be the finest in the United States. He bequeathed his mineral and archaeological collections to the Academy, along with his library and an endowment for their preservation.

Vaux was one of eight founders of the Numismatic and Antiquarian Society, its senior vice-president, and from 1871 till his death treasurer of the American Association for the Advancement of Science. Vaux also served as president of the Zoological Society of Philadelphia.