BirdAnalyst
Species · BCR 10 · BBS 2025 Release · 1966–2024

Nashville Warbler In Northern Rockies

All regionsNorthern RockiesForest birds

Nashville Warbler in Northern Rockies has surged: up 290% on the route-weighted index since 1970.

+290%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 →
75Routes 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 surged in Northern Rockies: up 290% on the route-weighted index since 1970.

Forecast

If the recent trend holds, Nashville Warbler in Northern Rockies is projected to rise about 18% by 2029 — from 0.60 in 2024 to a central estimate of 0.71 (95% range 0.39–1.0). A 5-year backtest shows a typical error of ±17.1%, with 100% of held-out values landing inside the 95% band.

+18%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 →
0.71Projected 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 →
0.39–1.095% 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 →
±17.1%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 Rockies is projected to rise about 18% by 2029 — from 0.60 in 2024 to a central estimate of 0.71 (95% range 0.39–1.0). A 5-year backtest shows a typical error of ±17.1%, 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 →
20250.670.351.00
20260.680.361.0
20270.690.371.0
20280.700.381.0
20290.710.391.0

Routes In Northern Rockies

Routes recording Nashville Warbler in Northern Rockies.
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 →
CusickWASHINGTON232024
Sullivan LkWASHINGTON161999
CentervilleIDAHO132019
NaplesIDAHO82024
Lolo PassIDAHO82019
SunbeamIDAHO81994
Omak CreekWASHINGTON82024
Sullivan Lake 2WASHINGTON82024
Fish CreekMONTANA62024
Twin LakesWASHINGTON62024
CurlewWASHINGTON62013
Salmon RiverIDAHO42013
NoxonMONTANA42023
Hells CanyonOREGON42022
KellerWASHINGTON42007
ChewelahWASHINGTON42021
LaurierWASHINGTON42022
L Pend O NwrWASHINGTON42024
ChallisIDAHO32021
CoolinIDAHO32024
Rochat DivdeIDAHO32023
Libby DamMONTANA32024
OchocoOREGON32024
Donelly 2OREGON32022
MivodenIDAHO22023

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