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Species · Oregon · BBS 2026 Release · 1966–2025

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 →
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 →
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 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 16% by 2030 — from 4.3 in 2025 to a central estimate of 5.0 (95% range 2.8–7.2). A 5-year backtest shows a typical error of ±20.5%, with 100% of held-out values landing inside the 95% band.

+16%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 →
5.0Projected 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 →
2.8–7.295% 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 →
±20.5%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 16% by 2030 — from 4.3 in 2025 to a central estimate of 5.0 (95% range 2.8–7.2). A 5-year backtest shows a typical error of ±20.5%, 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 →
20265.12.87.3
20275.12.87.3
20285.02.87.3
20295.02.87.3
20305.02.87.2

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
Imnaha4820251968
Elkton4720251972
Winberry4120231968
Garfield3420251973
Coquille3220251994
Hauser2919851970
Glasgow2920251986
Hazel Camp2020221975
Derby1919931968
Tualatin1820251968
Svensen1819921990
Lorane1720251994
Salado1620251968
Scio1620251971
Nicolai Mtn.1620251993
Canby1520251993
Twickenham1420252010
Malheur Nwr1319911991
Dayton1020251973
Catlow Rim1020161994
Umatilla920251989
Logdell820251972
Molalla720251994

Violet-green Swallow Population Trend in Other States

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