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Species · Oregon · BBS 2026 Release · 1966–2025

Tree Swallow Population Trend in Oregon

All statesAerial insectivores

Tree Swallow in Oregon has edged down: down 22% on the route-weighted index since 1970.

-22%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 →
118Routes 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 →
57YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Tree Swallow Trends in OregonNotable 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 Tree Swallow in Oregon. See the full index history below.

Tree Swallow Population Forecast in Oregon

If the recent trend holds, Tree Swallow in Oregon is projected to stay roughly flat through 2030, near 3.4 (95% range 1.6–5.3). A 5-year backtest shows a typical error of ±22.3%, with 100% of held-out values landing inside the 95% band.

+5%Change by 2030TrendPercent 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 →
3.4Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
1.6–5.395% 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 →
±22.3%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, Tree Swallow in Oregon is projected to stay roughly flat through 2030, near 3.4 (95% range 1.6–5.3). A 5-year backtest shows a typical error of ±22.3%, with 100% of held-out values landing inside the 95% band.19682030
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 →
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Tree Swallow Survey Routes in Oregon

Routes recording Tree Swallow in Oregon.
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 →
Modoc Point5520181969
Modoc Point 25320252024
Wedderburn4720251970
Molalla3920051994
Nicolai Mtn.3320251993
Derby2519931968
Dayton2120251974
Barnes Val1919871971
Emigrant Lk1720011972
Ordnance1419791974
Winberry1320211968
Glasgow1320251988
Adrian1220251985
Unity1220251997
Svensen1019921990
Mount Vernon920241987
Elkton820241973
Salem820251994
Deschutes720251968
Adair720251971
Fish Lake720251972
Summit Pr720251980
Myrtle Grove720041992
Fandango Can620231990
Paisley620251973

Tree Swallow Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomapennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.