Chimney swifts are small birds with wing length averaging 130.4 mm and tail length averaging 39.1 mm. They weigh approximately 21 grams. The bird's body and head are dark grayish to brownish-gray color on the upper part, slightly paler below. The tail has stiff bristle-like or spiny feather tips. There may be as many as seven tail spines. The eyes of chimney swifts are large. In flight these birds are described as looking like a "cigar with wings." Male and female birds look the same.
Chimney swifts are native to the Nearctic and Neotropical regions. They are found in North and South America, ranging from central Alberta to Newfoundland, then south to Florida, the Gulf States, and eastern Texas. They also migrate, spending the winters at the headwaters of the Amazon in western Brazil and eastern Peru. They are sometimes seen in Greenland and Bermuda.
In temperate zones, chimney swifts are found most often in areas settled by humans. In the tropics, they are also found near irrigated agricultural lands and areas inhabited by humans. In natural tropical settings, chimney swifts are found at the edge of rivers bordered by forest or the edge of lowland evergreen forests and secondary growth scrub, and even over the Andean valleys in Peru and Ecuador. They can be found at elevations of 2500 m. (Chantler and Driessens, 2000)
Chimney swifts are monogamous; records indicate that some chimney swifts will remain with the same mate for up to eight or nine years. (Dexter, 1969)
Chimney swifts gather together to breed in colonies. Some nesting colonies can be quite large, including thousands of individuals. The exact number of individuals varies depending on the size of the nesting area.
Chimney swifts build their nests in chimneys or hollow trees. The basket-like, half-cup nest is made of sticks secured to the inner wall of a chimney or tree by the hardened saliva of the swifts. The nest is usually placed at least 15.5 m off the ground, but this can vary greatly. A female lays 3 to 7 white, glossy eggs per clutch. Each egg is approximately 2.0 by 1.3 cm. Both parents help incubate the eggs, which means that they will take turns sitting on the nest to keep the eggs warm until they hatch. Nestlings may leave the nest 14 to 19 days after hatching but the first flight typically occurs 30 days after hatching. Chimney swifts probably reach sexual maturity (have the ability to breed) one year after they have left the nest.
Young chimney swifts are helpless when hatched and are fed by both parents.
Sometimes birds other than the breeding pair will help feed and care for young, a behavior called cooperative breeding. Chimney swifts are known to form cooperative breeding groups of three to four birds. These groups may remain as a nesting unit throughout the season, sharing incubation, brooding, and feeding duties. Records indicate that one colony had more than one-third of the breeding pairs form cooperative groups; there were 22 threesomes and 6 foresomes.
A female chimney swift was recorded to have lived ten years.
Chimney swifts use both their feet and tail to cling to vertical surfaces. These birds are highly gregarious, and several thousand may be found roosting in large industrial chimneys.
Migration begins in August and continues into early October. No chimney swifts have been recorded in the northern part of their range after October. They return in early spring, usually in April.
We do not have information on the home range for chimney swifts at this time.
Chimney swift calls are described as a twitter. The most common twitterings are accelerating and decelerating chipping.
Chimney swifts also are likely to use touch and vision in communication. They perceive their environment through vision, hearing, touch, and a weakly developed sense of smell.
Chimney swifts feed exclusively while in flight. They are primarily insectivores. They forage by hovering over tree branches and catching insects in flight; they take a variety of insect and spider prey. Forty to fifty chimney swifts were recorded hovering at the outer branches or diving through the top branches of a sweetgum tree in pursuit of a particular species of weevil.
As insectivores chimney swifts affect insect populations throughout their range.
There are no known adverse affects of chimney swifts on humans.
Chimney swifts are valuable as erradicators of insect pests. (Palmer and Fowler, 1975)
Chimney swifts have been described as being as peaceful as doves and always worthy of protection. They are protected by the Migratory Bird Treaty Act, but are not listed by CITES, US ESA or the IUCN.
Bird's nest soup is made from the nest of an Asiatic swift, a close relative of the chimney swift. The soup is based on the dried saliva that holds the nest together. Another close relative of chimney swifts are Vaux's swifts, Chaetura vauxi, which occur in the western United States.
From 1918 to 1932, over 1,600 people visited National, Iowa to study the nesting habits of chimney swifts in a tower designed by Althea Sherman and built in 1915 by local carpenters. The bird tower was approximately 8.5 meters high and 0.3 meters square. An artificial chimney, running down the center of the tower, measured approximately half the tower's height. A door and two glass windows allowed people to enter and observe the chimney swifts. After Althea Sherman's death, the tower was moved to the Andy Mountain Camp Ground, Harper's Ferry, Iowa. In the early 1980's, the tower was still standing and was being used for chimney swift studies.
Alaine Camfield (editor), Animal Diversity Web.
Janice Pappas (author), University of Michigan-Ann Arbor.
Chantler, P., G. Driessens. 2000. Swifts: A Guide to the Swifts and Treeswifts of the World, 2nd. ed. Sussex: Pica Press.
Dexter, R. 1969. Banding and nesting studies of the Chimney Swift, 1944-1968. The Ohio Journal of Science, 69(4): 193-213.
Dexter, R. 1952. Extra-parental cooperation in the nesting of Chimney Swifts. The Wilson Bulletin, 64(3): 133-139.
Dexter, R. 1956. Ten-year life history of a banded Chimney Swift. The Auk, 73: 276-280.
Palmer, E., H. Fowler. 1975. Fieldbook of Natural History, 2nd ed. New York: McGraw-Hill, Inc.
Whittemore, M. 1981. Chimney Swifts and Their Relatives. Jackson, MS: Nature Books Publishers.