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

Nashville Warbler In Northern Pacific Rainforest

All regionsNorthern Pacific RainforestForest birds

Nashville Warbler in Northern Pacific Rainforest has risen sharply: up 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 →
80Routes 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 →

Nashville Warbler has risen sharply in Northern Pacific Rainforest: up 64% on the route-weighted index since 1970.

Nashville Warbler In Northern Pacific Rainforest Population Forecast

If the recent trend holds, Nashville Warbler in Northern Pacific Rainforest is projected to rise about 97% by 2029 — from 1.6 in 2024 to a central estimate of 3.2 (95% range 0.84–5.5). A 5-year backtest shows a typical error of ±67.4%, with 100% of held-out values landing inside the 95% band.

+97%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 →
3.2Projected 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 →
0.84–5.595% 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 →
±67.4%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, Nashville Warbler in Northern Pacific Rainforest is projected to rise about 97% by 2029 — from 1.6 in 2024 to a central estimate of 3.2 (95% range 0.84–5.5). A 5-year backtest shows a typical error of ±67.4%, 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 →
20253.20.855.5
20263.20.855.5
20273.20.845.5
20283.20.845.5
20293.20.845.5

Routes In Northern Pacific Rainforest

Routes recording Nashville 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 →
South Fork MtnCALIFORNIA422022
ClearwaterOREGON392021
CarrvilleCALIFORNIA361970
Horse CreekCALIFORNIA312019
SelmaOREGON312024
RuchOREGON202023
ProspectOREGON192024
CinderellaOREGON172024
Hay ForkCALIFORNIA162017
Pilot CreekCALIFORNIA161996
Secret ValOREGON162022
Days CreekOREGON152024
Lonesome RdgCALIFORNIA142014
Mt. AdamsWASHINGTON122024
OrleansCALIFORNIA112012
Sams ValleyOREGON102024
Whiskey Spg.OREGON102022
MccloudCALIFORNIA92021
WhiskeytownCALIFORNIA92012
DerbyOREGON91993
MolallaOREGON92021
Friday RidgeCALIFORNIA82024
Ship Mtn.CALIFORNIA72017
HullvilleCALIFORNIA62019
Shasta LakeCALIFORNIA62007

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