BirdAnalyst
Species · Washington · BBS 2025 Release · 1966–2024

Bank Swallow Population Trend in Washington

All statesAerial insectivores

Bank Swallow in Washington has fallen sharply: down 69% on the route-weighted index since 1970.

-69%Since 1970TrendPercent 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 →
62Routes In StateSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
56YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Bank Swallow Trends in WashingtonNotable 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 Washington: down 69% on the route-weighted index since 1970.

Bank Swallow Population Forecast in Washington

If the recent trend holds, Bank Swallow in Washington is projected to stay roughly flat through 2029, near 4.4 (95% range 0.00–11). A 5-year backtest shows a typical error of ±116.8%, with 100% of held-out values landing inside the 95% band.

-7%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 →
4.4Projected 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 →
0.00–1195% 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 →
±116.8%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 in Washington is projected to stay roughly flat through 2029, near 4.4 (95% range 0.00–11). A 5-year backtest shows a typical error of ±116.8%, with 100% of held-out values landing inside the 95% band.19682029
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 →
20254.60.0011
20264.50.0011
20274.50.0011
20284.50.0011
20294.40.0011

Bank Swallow Survey Routes in Washington

Routes recording Bank Swallow in Washington.
Recent countThe raw number of individuals recorded on this route in its most recent survey year. A single-route tally, not a trend.Full methodology →
Pomona10019991998
Scootney Reservoir8020242009
Hanford Site7419961988
Mesa7120081995
Nighthawk6020241992
Yakima5220241993
Wapato4120221971
Ewan 22020242023
Ellensburg1820241984
Othello1619911981
Mercer1520061972
Ewan1520192006
Harrington1320121989
Laurier1120122005
Concrete1020242013
Wilbur820241985
Horn Rapids820242005
Chewelah620081987
Selah620002000
Cusick620171990
Twisp520221969
Everett520242017
Keller420071968
Snowden419891971
Prescott420221988

Bank Swallow Population Trend in Other States

alabamaalaskaarkansascaliforniacoloradoconnecticutdelawareidahoillinoisindianaiowakansaskentuckymainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-dakotatennesseetexasutahvermontvirginiawest-virginiawisconsinwyoming

Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.