Bank Swallow

Riparia riparia

(c) Scott Elowitz
  • HIRUNDINIDAE
  • Swallows, Martins
  • Passeriformes
  • Golondrina ribereña; Golondrina Barranquera
  • Hirondelle de rivage
Introduction
The Bank Swallow is rarely found far from water. Social and always active, this small brown and white bird nests in colonies sometimes numbering in the thousands. Wherever moving water makes steep walls in sand, dirt, or gravel, the Bank Swallow digs a tunnel for its nest with its small feet and bill. It is known as the Sand Martin in Europe.
Appearance Description
The smallest swallow in North America, the Bank Swallow weighs .47 ounces, grows to 5.25 inches, and has a 13-inch wingspan, on average. All adults appear similarly brown above and white from the chin to the under-tail. A brown band spans the chest, and helps distinguish this species from other swallows. With such short wings, the flight of the Bank Swallow is erratic, with rapid wing beats and little gliding.
Range Map
Courtesy Kenn Kaufman
Range Distribution
Bank Swallows breed over most of central North America from Arkansas northward to Alaska, then eastward to the Atlantic Provinces and south into Virginia. They winter throughout most of South America.
 
A legend for the range map to the right can be found here.
Habitat
Bank Swallows nest exclusively in the fresh banks or earthen walls cut by moving water, usually at lower elevations. They prefer meandering streams and rivers. Artificial banks created incidentally by mining are also used. Foraging and migrating occur over fields, streams, wetlands, farmlands, and still water.
Feeding
The Bank Swallow feeds and drinks almost exclusively on the wing. They consume bees, wasps, ants, beetles, and flies primarily from the air, but occasionally from the water surface. They eat no plant material.
Reproduction
Arriving before the females, male Bank Swallows select a colony, then a nest site 3 to 12 feet above the base of a bank or cliff. With his beak, the male begins to dig a hole, which the pair will finish together. The swallows use their bills, wings, and feet to excavate. Males perform several types of display flights to attract a female and defend the burrow. At the end of this two- to three-foot-long tunnel, a nest is constructed from plant materials, mostly grasses and rootlets. After 3 to 7 whitish eggs are laid, the female lines the nest with feathers.
 
Breeding appears to be synchronized within the colony. The pair incubates the eggs, which hatch in 13 to 15 days. The young require brooding for up to 10 days, and fledge in approximately 22 days. Fledglings return to their natal burrows, but also frequent their neighbors' active tunnels. They form small flocks to play, forage, and roost in nearby vegetation or empty burrows. Juveniles and adults flock after the breeding season and join other swallow species. Typically, Bank Swallows produce only one brood per season.
Migration
The Bank Swallow migrates long distances with flocks of other swallows during the day, moving from South America up the isthmus of Central America. Migration ranges from March to late May. Fall migration begins as soon as breeding ends and peaks early in the season.
  • 46,000,000
  • 13,800,000
  • no current conservation concerns
Population Status Trends
Bank Swallow populations are difficult to monitor, because their breeding locations change often, as the swallows abandon degraded banks. Some regions, like the Great Lakes, have seen Bank Swallows increase at breeding sites, while others have recorded steady losses—like California, which reported a 39% decrease in Bank Swallows from 1986 to 1991. Christmas Bird Count and Breeding Bird Survey data over 40 years indicate a slight decline in the overall population. Nevertheless, Bank Swallows remain widespread and fairly common over much of their range.
Conservation Issues
Natural water flow, which allows for seasonal flooding, produces the best habitat for Bank Swallows. In efforts to reduce erosion, produce hydroelectric power, and create reservoirs, water management practices have altered the river bank habitat required by Bank Swallows. All manner of bank stabilization along waterways tends to destroy traditional colony sites by disturbing occupied burrows, preventing natural erosion that would refresh bank faces, and changing steep banks to shallow slopes, regardless of benefit to other wildlife. Several states have placed the Bank Swallow on watch lists, and California has implemented a recovery plan for stabilizing their threatened population. Banks artificially dug for Bank Swallow have had only limited success and are very expensive, but open pit mines for gravel and sand have supported colonies in Virginia and Connecticut. Economic pressures have closed these mines and thus reduced suitable nesting sites.   When industrial mining sites are modified to create fresh, steep banks and when operations at these sites route excavation around colonies, Bank Swallows have thrived.
What You Can Do
Find an active Bank Swallow colony in your area and observe their active, social life.
 
In order to excavate nest tunnels, Bank Swallows must have fresh walls of sand or dirt. Support river and stream management that allows for the natural creation of earthen banks.
 
For actions you can take, including Audubon activities, please visit our resources page.
More Information
To learn more about the conservation issues and recovery efforts in California, visit the Habitat Conservation Planning Branch on the state's official website and read about the Bank Swallow Recovery Plan
 
Visit our resources page for more information about this species.
Natural History References
Bent, Arthur Cleveland. 1942. Life Histories of North American Flycatchers, Larks, Swallows and Their Allies. United States Government Printing Office, Washington, D.C.
 
Garrison, B. A. 1999. Bank Swallow (Riparia riparia). In The Birds of North America, No. 414 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA.
 
Kaufman, Kenn. Lives of North American Birds. Houghton Mifflin Company, New York, 1996.
 
Sibley, David Allen. 2000. The Sibley Guide to Birds. Alfred A. Knopf, New York.
Conservation Status References
Bent, Arthur Cleveland. 1942. Life Histories of North American Flycatchers, Larks, Swallows and Their Allies. United States Government Printing Office, Washington, D.C.
 
Garrison, B. A. 1999. Bank Swallow (Riparia riparia). In The Birds of North America, No. 414 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA.
 
Kaufman, Kenn. Lives of North American Birds. Houghton Mifflin Company, New York, 1996.
 
Schlorff, R.W. 1993. California Department of Fish and Game, Nongame Bird and Mammal Section. "Recovery Plan: Bank Swallow." (Report 93.02) 27 pp.
 
Sibley, David Allen. 2000. The Sibley Guide to Birds. Alfred A. Knopf, New York.