BirdAnalyst
Species · BCR 5 · BBS 2025 Release · 1966–2024

Hermit Warbler In Northern Pacific Rainforest

All regionsNorthern Pacific RainforestForest birds

Hermit Warbler in Northern Pacific Rainforest has risen sharply: up 57% on the route-weighted index since 1970.

+57%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 →
104Routes In RegionSurvey 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 SignalsNotable 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 increasecomputed 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 →

Hermit Warbler has risen sharply in Northern Pacific Rainforest: up 57% on the route-weighted index since 1970.

Hermit Warbler In Northern Pacific Rainforest Population Forecast

If the recent trend holds, Hermit Warbler in Northern Pacific Rainforest is projected to rise about 36% by 2029 — from 6.5 in 2024 to a central estimate of 8.8 (95% range 5.2–12). A 5-year backtest shows a typical error of ±25.9%, with 100% of held-out values landing inside the 95% band.

+36%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 →
8.8Projected 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 →
5.2–1295% 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 →
±25.9%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, Hermit Warbler in Northern Pacific Rainforest is projected to rise about 36% by 2029 — from 6.5 in 2024 to a central estimate of 8.8 (95% range 5.2–12). A 5-year backtest shows a typical error of ±25.9%, 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 →
20258.55.012
20268.65.012
20278.65.112
20288.75.212
20298.85.212

Routes In Northern Pacific Rainforest

Routes recording Hermit Warbler in Northern Pacific Rainforest.
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 →
ClearwaterOREGON1382021
FisherOREGON782010
RuchOREGON702023
Klickitat MtOREGON611996
Blue RiverOREGON592024
Trask SummitOREGON472024
Mt. AdamsWASHINGTON472024
Martins FyCALIFORNIA462009
Pilot CreekCALIFORNIA461996
Friday RidgeCALIFORNIA392024
Hazel CampOREGON362022
Lonesome RdgCALIFORNIA342014
Cool CampOREGON342013
LoraneOREGON302024
South Fork MtnCALIFORNIA292022
Warner Mtn.OREGON292024
Redwood N.P. 2CALIFORNIA272013
CinderellaOREGON262024
Harlan 2OREGON252024
Fisher 2OREGON252024
Nicolai Mtn.OREGON242024
SelmaOREGON222024
HarlanOREGON182009
HiouchiCALIFORNIA142014
Secret ValOREGON132022

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