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

Tree Swallow Population Trend in Oregon

All statesAerial insectivores

Tree Swallow in Oregon has declined: down 31% on the route-weighted index since 1970.

-31%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 →
115Routes 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 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 2029, near 3.5 (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.

+6%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 →
3.5Projected 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 →
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 2029, near 3.5 (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.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 →
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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 Point 27920242024
Modoc Point5520181969
Molalla3920051994
Coquille3220241994
Deschutes2620241968
Derby2519931968
Ruch2120231992
Barnes Val1919871971
Emigrant Lk1720011972
Ordnance1419791974
Winberry1320211968
Wedderburn1320241970
Glasgow1320241988
Adair1120231971
Dayton1120241974
Mt Hood1120241972
Adrian1119931985
Svensen1019921990
Albee920241969
Mount Vernon920241987
Bridgeport820221987
Elkton820241973
Summit Pr820241980
Emigrant Lake 2820242002
Days Creek720241971

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 2026-05-22.