BirdAnalyst
Species · BBS 2025 Release · 1966–2024

Bank Swallow

HirundinidaeAerial insectivoresRiparia riparia

Bank Swallow has fallen sharply: down 74% on the route-weighted index since 1968.

-74%Since 1968TrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →
1,615RoutesSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
58Years SurveyedYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

About the Bank Swallow

The smallest North American swallow, the Bank Swallow digs nest burrows in colonies in sandy banks and bluffs.

Size
4.5 in long, about 0.5 oz (12 cm, 14 g)
Habitat
Open airspace over fields, water and towns; nests in cavities, earthen banks or on structures.
Diet
Small flying insects caught low over water and open ground.
Range
Recorded on 1,615 Breeding Bird Survey routes across 44 states, most concentrated in the Eastern Tallgrass Prairie.
Family
Hirundinidae · Aerial insectivores
Conservation
Least Concern

Notable Bank Swallow TrendsNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

long arc declinecomputed indexTrend sourceWhether the figure is our own computed route-weighted index or an official USGS modeled estimate. The current build labels every trend as computed.Full methodology →

Bank Swallow has fallen sharply in surveyed states: down 74% on the route-weighted index since 1968.

Bank Swallow Population Forecast

If the recent trend holds, Bank Swallow is projected to stay roughly flat through 2029, near 0.62 (95% range 0.00–1.2). A 5-year backtest shows a typical error of ±39.2%, with 100% of held-out values landing inside the 95% band.

+2%Change by 2029TrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →
0.62Projected 2029 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–1.295% range95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →
±39.2%Backtest errorBacktest errorTypical error when we hold out the most recent years, forecast them, and compare to what actually happened. Lower means a more trustworthy projection.Full methodology →
If the recent trend holds, Bank Swallow is projected to stay roughly flat through 2029, near 0.62 (95% range 0.00–1.2). A 5-year backtest shows a typical error of ±39.2%, with 100% of held-out values landing inside the 95% band.19662029
Projection of the recent trend (dashed) with 80/95% bands — a projection, not a prediction. Habitat, climate, and land use are not modeled.
YearProjected indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →95% low95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →95% high95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →
20250.730.111.3
20260.700.081.3
20270.680.061.3
20280.650.031.3
20290.620.001.2

Where the Bank Swallow Is Detected

BBS routes recording Bank Swallow, sized by most recent count.

Bank Swallow Population Trend by State

Bank Swallow population trend by state.
TrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →Baseline yearThe first year of the smoothed window the trend is measured from. An earlier baseline means a longer record stands behind the number.Full methodology →Survey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
Alabamainsufficient datan/a3
Alaska-82%197691
Arkansas-53%19924
California+505%197127
Colorado-54%197335
Connecticut+77%196817
Delaware+10%19698
Idaho-63%197039
Illinois-95%196860
Indiana-82%196947
Iowa-92%196934
Kansas-82%196938
Kentucky+15%197710
Maine-92%196852
Maryland-82%196830
Massachusetts-53%196828
Michigan-44%196889
Minnesota-74%196973
Mississippiinsufficient datan/a1
Missouri-13%197227
Montana-75%197070
Nebraska-56%196940
Nevada+2%199611
New Hampshire-97%196824
New Jersey-67%196818
New Mexico-86%19735
New York-88%1968108
North Carolina-88%19777
North Dakota-0%196951
Ohio-68%196849
Oklahoma-70%196916
Oregon+501%197143
Pennsylvania-85%196860
Rhode Islandinsufficient datan/a1
South Dakota-81%196941
Tennessee+448%198012
Texas-92%196927
Utah-96%197431
Vermont-93%196824
Virginia-72%197215
Washington-69%197062
West Virginia-97%197616
Wisconsin-91%196886
Wyoming-5%197185

Bank Swallow Population Trend by Region

Bird Conservation Regions are the ecological unit for trends.

Bank Swallow population trend by Bird Conservation Region.
TrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →Baseline yearThe first year of the smoothed window the trend is measured from. An earlier baseline means a longer record stands behind the number.Full methodology →Survey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
BCR 2-68%198522
BCR 4-79%197657
Northern Pacific Rainforest+53%197427
Great Basin-42%1970129
Northern Rockies-80%1970130
Prairie Potholes-2%1969111
Boreal Hardwood Transition-92%196893
Lower Great Lakes / St. Lawrence Plain-84%196873
Atlantic Northern Forest-94%1968122
Southern Rockies / Colorado Plateau-87%197445
Badlands and Prairies+1%196977
Shortgrass Prairie-97%196927
Central Mixed Grass Prairie-62%196954
Oaks and Prairies-10%197011
Eastern Tallgrass Prairie-90%1968163
Prairie Hardwood Transition-86%1968147
Central Hardwoods+7%197537
Mississippi Alluvial Valley-97%19805
Southeastern Coastal Plain-46%19898
Appalachian Mountains-95%1968130
Piedmont-80%196826
New England / Mid-Atlantic Coast-74%196887
Coastal California-95%197211
Tamaulipan Brushlands-86%197010

Bank Swallow Conservation Status

Least Concern

The IUCN Red List rates this species as Least Concern. Our route-weighted index shows it down about 74% since 1968. Aerial insectivores have fallen sharply across the continent, a decline widely linked to dwindling insect prey.

Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22. Trend is a route-weighted relative-abundance index, not an absolute population.