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

Barn Swallow Population Trend in Washington

All statesAerial insectivores

Barn Swallow in Washington has declined: down 37% on the route-weighted index since 1970.

-37%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 →
103Routes 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 Barn 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 →

No notable trend signals for Barn Swallow in Washington. See the full index history below.

Barn Swallow Population Forecast in Washington

If the recent trend holds, Barn Swallow in Washington is projected to fall about 16% by 2029 — from 8.7 in 2024 to a central estimate of 7.3 (95% range 0.65–14). A 5-year backtest shows a typical error of ±15.6%, with 100% of held-out values landing inside the 95% band.

-16%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 →
7.3Projected 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 →
0.65–1495% 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 →
±15.6%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, Barn Swallow in Washington is projected to fall about 16% by 2029 — from 8.7 in 2024 to a central estimate of 7.3 (95% range 0.65–14). A 5-year backtest shows a typical error of ±15.6%, 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 →
20258.31.715
20268.11.415
20277.81.214
20287.60.9114
20297.30.6514

Barn Swallow Survey Routes in Washington

Routes recording Barn 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 →
Potholes8020231996
Scootney Reservoir5020242009
Raymond4520211993
Warm Beach4420171968
Othello4419911981
Pe Ell4120231993
Mesa4020081994
Ellensburg3420241981
Quincy3320241981
Columbia Nwr3320221992
Harrington3220121972
Harwood3219971993
Carnation3120241988
Camas2920091971
South Elma2820241975
Mukilteo2820241993
Cougar2720231968
Montesand2720241986
Selah2620232000
Issaquah2319871969
Moses Lake2320221973
Raymond 22320242022
Ewan 22120232023
Port Angeles2020241970
Hartline2020241994

Barn Swallow Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawest-virginiawisconsinwyoming

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