Black Swift Survey

Photo: © Bill Schmoker http://schmoker.org/BirdPics

The Black Swift is one of most unusual, mysterious, and sought after birds in western North America. Since 2003, ABC and a variety of partners and numerous citizen volunteers have been conducting surveys to learn more about the nesting locations of this species to determine its status and conservation needs.

The Black Swift is a small swallow-like bird with black plumage and long, relatively thin, scythe-shaped wings. They nest almost exclusively at waterfalls where they place their nest on a moss-covered ledge or crevice in the rock behind the veil of falling water, which they must fly through to get to their nest. Adult Black Swifts spend their days high in the sky, often near the limit of human visibility. Here they hunt flying insects, which they swallow and accumulate into large masses to regurgitate to their chicks. They may travel as many as 50 miles away to forage each day, so the best time to see them at the nest site is just before dark when they return to feed their chicks and roost for the night.

Many of the characteristics of their unique nesting ecology are directly related to the place where they nest. Predation is rare because of the inaccessibility of the nest site, thus each pair only lays one egg and they only attempt one nest per year. Unlike most small landbirds, there is no urgency in incubation and rearing of the young because of the security provided by their nest site, so Black Swifts have incubation and nestling periods twice as long as most birds of similar size; 24-28 days for incubation and 40-45 days for the nestling period.

Adults feed young infrequently; up to 3-8 hours between feeding bouts for young up to 2 weeks old, but perhaps only twice a day for an older nestling. Food is fed as a "bolus" or conglomeration of insects accumulated by the adult over several hours of foraging, and then regurgitated to the nestling.

Black Swifts nest in mountain ranges scattered from southeastern Alaska to western Mexico and Central America, and islands in the West Indies. However, less than 250 nesting sites are known and they are apparently absent from large areas, including the many waterfalls in Yellowstone and Grand Teton National Parks.

Black Swifts have high nest site fidelity. All of the colonies located in Colorado in the 1950s remain active today, and each of the colonies seems to be much the same size as it was then. Nest sites are reused year after year.

Our knowledge about their non-breeding season behavior and ecology is almost non-existent. The best answer to where do they winter is "somewhere in South America." This is based on a few scattered records during migration that suggest birds move over land and sea from southern Mexico into northern South America .

The recent interest in the Black Swift (an ABC WatchList species) was kick-started with the development of Partners in Flight Bird Conservation Plans which have identified Black Swift as a priority species for conservation in every western state in which the species resides. A protocol was developed for visiting and inventorying waterfalls, and pioneering monitoring efforts in Colorado and California greatly enhanced our knowledge about the species. An ABC-lead inventory in Oregon , Washington , and southeast Alaska in 2003-2005 raised the number of likely nesting sites from around 5 to over 25. The success of these recent inventories is due primarily to many dedicated and motivated volunteers. Over 100 volunteers have assisted ABC in Oregon and Washington, and are helping to move this bird from the list of least-known species to one of the best-monitored species.