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

Violet-green Swallow Population Trend in Oregon

All statesAerial insectivores

Violet-green Swallow in Oregon has declined: down 27% on the route-weighted index since 1970.

-27%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 →
112Routes 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 Violet-green 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 Violet-green Swallow in Oregon. See the full index history below.

Violet-green Swallow Population Forecast in Oregon

If the recent trend holds, Violet-green Swallow in Oregon is projected to rise about 39% by 2029 — from 3.7 in 2024 to a central estimate of 5.1 (95% range 2.9–7.3). A 5-year backtest shows a typical error of ±17.9%, with 100% of held-out values landing inside the 95% band.

+39%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 →
5.1Projected 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 →
2.9–7.395% 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 →
±17.9%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, Violet-green Swallow in Oregon is projected to rise about 39% by 2029 — from 3.7 in 2024 to a central estimate of 5.1 (95% range 2.9–7.3). A 5-year backtest shows a typical error of ±17.9%, 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 →
20255.12.97.4
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20295.12.97.3

Violet-green Swallow Survey Routes in Oregon

Routes recording Violet-green 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 →
Sandy River9220061993
Ordnance6919781978
Glasgow4820241986
Winberry4120231968
Garfield3520231973
Hauser2919851970
Coquille2620241994
Clover Creek2520221976
Scio2220241971
Elkton2220241972
Hazel Camp2020221975
Secret Val2020221975
Santiam2020241994
Derby1919931968
Salado1820241968
Svensen1819921990
Scappoose1620231995
Tualatin1520241968
Wedderburn1420241970
Dayton1420241973
Mt Hood1320241972
Malheur Nwr1319911991
Canby1320241993
Imnaha1120241968
Unity1020231998

Violet-green Swallow Population Trend in Other States

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