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

Hermit Warbler Population Trend in Oregon

All statesForest birds

Hermit Warbler in Oregon has increased: up 45% on the route-weighted index since 1970.

+45%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 →
59Routes 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 Hermit Warbler 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 Hermit Warbler in Oregon. See the full index history below.

Hermit Warbler Population Forecast in Oregon

If the recent trend holds, Hermit Warbler in Oregon is projected to rise about 67% by 2029 — from 4.0 in 2024 to a central estimate of 6.8 (95% range 3.8–9.7). A 5-year backtest shows a typical error of ±43.4%, with 60% of held-out values landing inside the 95% band.

+67%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 →
6.8Projected 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 →
3.8–9.795% 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 →
±43.4%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, Hermit Warbler in Oregon is projected to rise about 67% by 2029 — from 4.0 in 2024 to a central estimate of 6.8 (95% range 3.8–9.7). A 5-year backtest shows a typical error of ±43.4%, with 60% 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 →
20256.53.69.5
20266.63.69.6
20276.73.79.6
20286.73.79.7
20296.83.89.7

Hermit Warbler Survey Routes in Oregon

Routes recording Hermit Warbler 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 →
Clearwater13820211991
Fisher7820101997
Ruch7020231992
Klickitat Mt6119961993
Blue River5920241992
Trask Summit4720241992
Hazel Camp3620221975
Cool Camp3420131968
Lorane3020241993
Warner Mtn.2920241992
Cinderella2620241993
Harlan 22520242011
Fisher 22520242017
Nicolai Mtn.2420241993
Selma2220241993
Harlan1820092006
Molalla1320241994
Secret Val1320221975
Shellrock1220231968
Timber1120171974
Waldport1120011992
Coquille1120241996
Myrtle Grove1020241992
Bull Run920242007
Glasgow820241986

Hermit Warbler Population Trend in Other States

californiawashington

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