Montana Field Guide

Black Swift - Cypseloides niger

Black Swifts are the largest of the swifts in North America. They are over 7 inches in length and have wingspans up to 18 inches. As the name implies, Black Swifts are completely dark in appearance. A distinctly notched tail on the adult male is the only difference in appearance between the sexes. They have long, broad-based, and curved wings, similar to hummingbirds. The tail is square and often fanned. Juveniles are similar in appearance to adults, except for the small bands of white present across much of the underbody (neck, belly, and undertail coverts). The wingbeats are slow and shallow, often looking erratic in flight when foraging (Sibley 2000).

Black Swift vocalizations are usually low, twittering chips, often rapidly repeating and slowing down at the end. Call notes are higher, clearer and sometimes similar to the Red Crossbill (Loxia curvirostra); a sharp "gyp" or "kip" (Sibley 2000).

The coloration of Black Swifts distinguishes them from White-throated Swifts (Aeronautes saxatalis), which have broad white markings on the chin, neck, breast, and sides of the rump. Black Swifts are much larger, have longer tails and are darker than Vaux's Swift (Chaetura vauxi). The same is true in comparison to Chimney Swifts (Chaetura pelagica), which also barely overlaps in range with Black Swifts.

Montana Range

Little information regarding the migratory patterns of Black Swifts exists for Montana. Birds have been observed in migration as early as May and as late as August (MBD 2003). All observations of migration or transitory behavior have occurred in the western part of the state, usually in areas where mountainous habitat exists including the Lolo Peak area in Missoula County, Lee Metcalf National Wildlife Refuge, and the National Bison Range (MBD 2003).

No specific information regarding Black Swift habitat exists for Montana. Information from other regions indicates they forage over forests and in open areas. They nest behind or next to waterfalls and wet cliffs (Michael 1927, Knorr 1961, Foerster and Collins 1990), on sea cliffs and in sea caves (Vrooman 1901, Legg 1956), and occasionally in limestone caves (Davis 1964). Nests are located in dark, inaccessible sites with an unobstructed flight path (Knorr and Knorr 1990). Nest site persistence and tenacity is almost absolute (Knorr and Knorr 1990). The nest is a cup-like structure of mud, mosses and algae.

Black Swifts feed on insects (e.g., flying ants, caddisflies, mayflies, beetles, flesh flies, hymenopterans). They catch insects in the air, often at great heights and often forage with other swifts at the leading edges of rainstorms (Costa Rica) (Stiles and Skutch 1989).

Little information exists regarding Black Swift reproduction in Montana as no systematic surveys have been completed in the state. Information from other areas within the Black Swifts' range indicates they nest in small colonies. A single egg is laid in June to July. The nestling is altricial and fledges in approximately 45 days.

Elsewhere, five factors present at nest sites include water, high relief, inaccessibity, shade, and unobstructed flyways (Knorr 1961). In Montana all nests found conform to this (Hunter and Baldwin 1962).

No active management currently is in place for Black Swifts in Montana. Although decreases in water flow and increased recreational use in areas where Black Swifts nest, or are thought to nest, should be discouraged (Casey 2000).