Black Swift
At a Glance
The largest swift normally found in North America, uncommon and local in the far west. Where it occurs, it may be seen flying very high, gliding and wheeling gracefully in pursuit of flying insects. The Black Swift seems to be limited in range by its very particular choice of nesting sites: it requires shady, sheltered spots on vertical cliffs totally inaccessible to predators, and often nests on the damp rock behind waterfalls.
All bird guide text and rangemaps adapted from Lives of North American Birds by Kenn Kaufman© 1996, used by permission of Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Category
Swallow-like Birds, Swifts
IUCN Status
Vulnerable
Habitat
Arroyos and Canyons, Coasts and Shorelines, Forests and Woodlands, High Mountains
Region
Alaska and The North, California, Northwest, Rocky Mountains, Southwest, Western Canada
Behavior
Direct Flight, Rapid Wingbeats, Swooping
Population
170.000
Range & Identification
Migration & Range Maps
Summer resident in North America, arriving in late spring, departing in early fall. Their winter range was unknown until very recently, but studies with geolocators (published in 2012) have revealed that at least some of the birds spend the winter in western Brazil.
Description
7-7 1/2" (18-19 cm). Larger than other swifts, tail moderately long, slightly forked. Mostly uniform blackish gray; at close range, shows frosting of whitish on forehead. High overhead, might suggest Purple Martin but has much longer, narrower wings.
Size
About the size of a Robin, About the size of a Sparrow
Color
Black, Gray
Wing Shape
Long, Narrow, Pointed, Swept, Tapered
Tail Shape
Notched, Square-tipped
Songs and Calls
Less vocal than other swifts. Gives soft, high-pitched twitter: twit-twit-twit-twit.
Call Pattern
Flat
Call Type
Chirp/Chip, Trill
Habitat
Open sky over mountains, coastal cliffs. Forages widely over any kind of terrain but is still very local in its occurrence, probably limited to regions with suitable nesting sites. Nests on ledges or in crevices in steep cliffs, either along coast or near streams or waterfalls in mountains.
Sign up for Audubon's newsletter to learn more about birds like the Black Swift
Behavior
Eggs
1. White, becoming nest-stained. Incubation is by both parents, 24-27 days.
Young
Both parents feed and care for young bird, which remains in nest until ready to fly (not climbing about like the young of some other swifts). Age at first flight about 45-49 days.
Feeding Behavior
Forages only while flying. Flight is rapid and often very high; bird scoops insects out of the air with its wide bill. May forage singly or in small flocks.
Diet
Flying insects. Feeds on a wide variety of flying insects, including wasps, flies, mayflies, caddisflies, beetles, and others, also spiders. At times may feed heavily on emerging swarms of winged adult ants or termites.
Nesting
Courtship apparently involves long aerial chases, and the birds also mate while flying. May nest in small colonies. Nest site is on ledge sheltered by overhang or in protected crevice on cliff, along rocky coast or in mountainous country. Mountain nest sites are often behind waterfalls, in spots where nest is continuously damp from spray. Sites are usually inaccessible. Nest is a small saucer of mud, moss, ferns, sometimes lined with fine plant material. Same site may be reused for years, with material added each time.
Climate Vulnerability
Conservation Status
Uncommon and local, and surveys suggest that populations have been declining significantly in recent years.
Climate Threats Facing the Black Swift
Choose a temperature scenario below to see which threats will affect this species as warming increases. The same climate change-driven threats that put birds at risk will affect other wildlife and people, too.