|Species: Northern Rough-winged
Rough-winged Swallow is brown-backed, dusky-throated.
the United States of America, northern Mexico and southwestern parts
of Canada, wintering in southern tip of Florida, and southern Mexico
Warmish brownish-gray underparts, whitish underparts; grayish wash
on chin, throat and upper breast; long wings; tiny bill; forked
Larger and stockier
than Bank Swallow, with broader wings; shorter, square tail; bulkier
plain brown with drab, no contrasting markings, buffy throat, pale
bases of flight feathers translucent, broad white under tail coverts
visible from above.
Same as adult male
Plain, drab below with dusky throat, plain brown above.
Juvenile May-November buffy throat, bright cinnamon wing-bars.
Bank Swallow Riparia riparia
Diet: Entirely insects; occasionally taken from ground
The Northern Rough-winged Swallow is an aerial forager adept at
low-elevation flight over fields and along narrow gullies and other
irregular terrain. It feeds over water more than most species of
swallows and occasionally picks floating insects from the water
surface. Although fairly common throughout its breeding range, which
includes virtually all of North America south of southern Canada, it
is a bird that is easily missed. Breeding Bird Survey data show that
of all North American swallows, this species has by far the fewest
individuals counted per route where observed
Breeding: Open country, savanna, especially near running water. One
brood. Mating system is monogamous.
Displays: In courtship flight, males pursue females, displaying
white feathers at lower base of tail
Nest: At end of burrow 4 to 5 feet (1 to 6 feet) deep, or in other
cavity or niche; of grass, leaves, weed stems, occasionally moist
horse dung, no feather lining. In addition to occasionally
excavating burrows, nest in deserted kingfisher burrows, rodent
holes, and a wide variety of niches under bridges and wharves, in
culverts, sewer pipes, etc. Both sexes help with nest construction.
unmarked. 0.7" (18 mm).
Female incubates. Incubation takes 12 days. Development is altricial
(immobile, downless, eyes closed, fed). Young leave the nest after
19-21 days. Both sexes tend young.
These swallows prefers open areas and nests singly or in small
colonies in burrows or crevices, including those in human-made
occasionally loosely colonial. Often nest in Bank Swallow colony,
where they perch on roots protruding from bank, something Bank
Swallows never do. Function of serrations on outer primary feathers
(from which name is derived) is unknown; possibly function to
produce sounds in courtship flight.
Because the form of
the nest varies from habitat to habitat, and must be adapted to fit
a bewildering diversity of supporting structures, it is not
surprising that an almost limitless variety of materials (including
stones and mud, animal and plant products, and human-made artifacts)
have at one time or another been incorporated into nests. Avian
products that become part of nests include saliva (the main
ingredient in cave swiftlet nests used in Chinese "bird's nest"
soup), ejected pellets, feathers, down, and guano. Feathers are
highly valued, in part because of their capacity to trap air and
provide insulation. Products of other animal species may include
silk from cocoons and spider webs, cast snake skins, hair, fur, bits
of cow pats, shells, etc. The variety of plant and manufactured
products found in nests is enormous, including virtually anything
that can be carried.
This swallow’s most
distinguishing characteristic is its “rough” primary feather, from
which its common name has been derived (see Fig. 6). In adults the
stiffened barbs of the leading web of the outer primary feather lack
terminal barbules. In males the barbs are recurved into minute
hooklets, and in the female they are prolonged into a definite,
naked point that is little or not at all recurved. In males this
produces “a file-like roughness when the finger is drawn along the
edge of the quill from base toward tip” (Ridgway 1904). Early
taxonomists were so taken with this characteristic that they
referred to it in both the genus and species portions of this bird’s
scientific name. The Greek appellation for the genus,
Stelgidopteryx, is a combination of two words meaning “scraper
wing,” and the species name of serripennis, assigned by Audubon, is
a combination of two Latin words meaning “saw feather.” The possible
adaptive significance of this feature remains a mystery.
Rough-winged Swallow has adapted well to environmental changes
caused by human activity and is presently not listed as a
Small numbers of this usually solitary aerial insectivore
arrive at Colony Farms in late May. This, as well as being
difficult to capture, is reflected by low capture rates of
Northern Rough-winged Swallows during June and July. Capture
rates are standardized as birds captured per 100 net hours
from 2010 - 2012.