BirdAnalyst
Species · BCR 15 · BBS 2026 Release · 1966–2025

Nashville Warbler In Sierra Nevada

All regionsSierra NevadaForest birds

Nashville Warbler in Sierra Nevada has increased: up 29% on the route-weighted index since 1973.

+29%Since 1973TrendPercent 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 →
35Routes 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 →
54YearsYears 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 →

No notable trend signals for Nashville Warbler in Sierra Nevada. See the full index history below.

Nashville Warbler In Sierra Nevada Population Forecast

If the recent trend holds, Nashville Warbler in Sierra Nevada is projected to rise about 62% by 2030 — from 6.3 in 2025 to a central estimate of 10 (95% range 6.4–14). A 5-year backtest shows a typical error of ±27.8%, with 80% of held-out values landing inside the 95% band.

+62%Change by 2030TrendPercent 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 →
10Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
6.4–1495% 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 →
±27.8%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 Sierra Nevada is projected to rise about 62% by 2030 — from 6.3 in 2025 to a central estimate of 10 (95% range 6.4–14). A 5-year backtest shows a typical error of ±27.8%, with 80% of held-out values landing inside the 95% band.19712030
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 →
20269.96.214
202710.06.314
2028106.314
2029106.414
2030106.414

Routes In Sierra Nevada

Routes recording Nashville Warbler in Sierra Nevada.
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 →
Forest Hill 2CALIFORNIA342005
Bass LakeCALIFORNIA322011
PlacervilleCALIFORNIA232025
Tahoe NfCALIFORNIA171994
Hat CreekCALIFORNIA162018
Tuolumne GroveCALIFORNIA152025
RivertonCALIFORNIA142025
JohnsvilleCALIFORNIA122025
Butte MeadowCALIFORNIA122014
DownievilleCALIFORNIA102025
WawonaCALIFORNIA92025
LumberyardCALIFORNIA72025
Greenhorn MtCALIFORNIA72008
Lassen ParkCALIFORNIA51981
Meadow ValleyCALIFORNIA52025
WestvilleCALIFORNIA42025
DardanelleCALIFORNIA42019
GeneseeCALIFORNIA42024
LakeshoreCALIFORNIA42024
PaxtonCALIFORNIA42025
Silver CityCALIFORNIA32013
Kings CanyonCALIFORNIA32011
Little TruckeeCALIFORNIA32025
Forest HillCALIFORNIA32025
StrawberryCALIFORNIA32019

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.