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

Purple Finch Population Trend in Oregon

All statesGeneralists

Purple Finch in Oregon has collapsed: down 78% on the route-weighted index since 1970.

-78%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 →
80Routes 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 Purple Finch 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 →

long arc declinecomputed indexTrend sourceWhether the figure is our own computed route-weighted index or an official USGS modeled estimate. The current build labels every trend as computed.Full methodology →

Purple Finch has collapsed in Oregon: down 78% on the route-weighted index since 1970.

Purple Finch Population Forecast in Oregon

If the recent trend holds, Purple Finch in Oregon is projected to fall about 53% by 2029 — from 0.99 in 2024 to a central estimate of 0.46 (95% range 0.00–2.4). A 5-year backtest shows a typical error of ±56%, with 100% of held-out values landing inside the 95% band.

-53%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 →
0.46Projected 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 →
0.00–2.495% 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 →
±56%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, Purple Finch in Oregon is projected to fall about 53% by 2029 — from 0.99 in 2024 to a central estimate of 0.46 (95% range 0.00–2.4). A 5-year backtest shows a typical error of ±56%, 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 →
20250.630.002.5
20260.590.002.5
20270.550.002.4
20280.510.002.4
20290.460.002.4

Purple Finch Survey Routes in Oregon

Routes recording Purple Finch 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 →
Granite3019891989
Coquille1220241994
Hauser1119851970
Mt Hood920241972
Badger Creek920241992
Secret Val720221975
Wizard Falls720222018
Sandy River620061993
Tualatin520241969
Scio520241975
Nicolai Mtn.520241993
Desolation519931993
Lorane520241993
Wedderburn420231970
Svensen419921990
Summit Pr420132009
Green420241994
Klickitat Mt419961993
Salem420241993
Prospect420241993
Riley Peak420161994
Shellrock320171968
Ochoco319761973
Winberry320231968
Hazel Camp320221975

Purple Finch Population Trend in Other States

alaskacaliforniaconnecticutindianamainemarylandmassachusettsmichiganminnesotanew-hampshirenew-jerseynew-yorknorth-dakotaohiopennsylvaniarhode-islandvermontwashingtonwest-virginiawisconsin

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