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

Great Horned Owl Population Trend in Oregon

All statesGeneralists

Great Horned Owl in Oregon has fallen sharply: down 54% on the route-weighted index since 1970.

-54%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 →
96Routes 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 Great Horned Owl 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 →

Great Horned Owl has fallen sharply in Oregon: down 54% on the route-weighted index since 1970.

Great Horned Owl Population Forecast in Oregon

If the recent trend holds, Great Horned Owl in Oregon is projected to fall about 34% by 2029 — from 0.18 in 2024 to a central estimate of 0.12 (95% range 0.00–0.30). A 5-year backtest shows a typical error of ±45.2%, with 100% of held-out values landing inside the 95% band.

-34%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 →
0.12Projected 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 →
0.00–0.3095% 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 →
±45.2%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, Great Horned Owl in Oregon is projected to fall about 34% by 2029 — from 0.18 in 2024 to a central estimate of 0.12 (95% range 0.00–0.30). A 5-year backtest shows a typical error of ±45.2%, 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 →
20250.130.000.31
20260.130.000.31
20270.120.000.31
20280.120.000.31
20290.120.000.30

Great Horned Owl Survey Routes in Oregon

Routes recording Great Horned Owl 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 →
Montague320241980
Clover Creek319891974
Modoc Point 2320242024
Summit Pr320101980
Tualatin219761976
Lone Rock220241999
Wickiup220151970
Bridgeport220071986
Joseph219731973
Dayton219901974
Mount Vernon220221986
Silver Creek220241984
Secret Val219841980
Wizard Falls220122001
Emigrant Lake 2220172017
Badger Creek220161995
Mikkalo220122012
Howard Mdws.219991999
Barnhouse220122012
Coquille219941994
Bald Mtn.219961996
Green Mtn.220001996
Monument220082008
Lorane220232022
Paunina220112011

Great Horned Owl 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.