BirdAnalyst
Species · Oregon · BBS 2026 Release · 1966–2025

Fox Sparrow Population Trend in Oregon

All statesForest birds

Fox Sparrow in Oregon has fallen sharply: down 65% on the route-weighted index since 1970.

-65%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 →
61Routes 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 Fox Sparrow 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 →

Fox Sparrow has fallen sharply in Oregon: down 65% on the route-weighted index since 1970.

Fox Sparrow Population Forecast in Oregon

If the recent trend holds, Fox Sparrow in Oregon is projected to fall about 78% by 2030 — from 1.3 in 2025 to a central estimate of 0.29 (95% range 0.00–1.7). A 5-year backtest shows a typical error of ±86.9%, with 100% of held-out values landing inside the 95% band.

-78%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 →
0.29Projected 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 →
0.00–1.795% 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 →
±86.9%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, Fox Sparrow in Oregon is projected to fall about 78% by 2030 — from 1.3 in 2025 to a central estimate of 0.29 (95% range 0.00–1.7). A 5-year backtest shows a typical error of ±86.9%, 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 →
20260.390.001.8
20270.360.001.8
20280.340.001.8
20290.310.001.8
20300.290.001.7

Fox Sparrow Survey Routes in Oregon

Routes recording Fox Sparrow 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 →
Davis Lake4420252000
Wizard Falls2220252000
Lapham Res.1220251993
Sisters1120251997
Paunina720251995
Ruch619951995
Dell Spring419961968
Clearwater420211991
Badger Creek420251992
Troy320251997
Ochoco320212016
Eagle Creek320252025
Albee220252013
Summit Pr220131990
Logdell220251971
Buchanan219841973
Mt Hood220251972
Pendleton220122012
Elk Lake220251972
Madras220122012
Newbridge220252025
Warner Mtn.220241992
Donelly 2220252024
Whiskey Spg.220111992
Desolation219991999

Fox Sparrow Population Trend in Other States

alaskacaliforniacoloradoidahomainemontananevadautahwashingtonwyoming

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