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

Black-throated Gray Warbler In Sierra Nevada

All regionsSierra NevadaForest birds

Black-throated Gray Warbler in Sierra Nevada has surged: up 257% on the route-weighted index since 1971.

+257%Since 1971TrendPercent 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 →
30Routes 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 →

Black-throated Gray Warbler has surged in Sierra Nevada: up 257% on the route-weighted index since 1971.

Black-throated Gray Warbler In Sierra Nevada Population Forecast

If the recent trend holds, Black-throated Gray Warbler in Sierra Nevada is projected to rise about 47% by 2030 — from 3.6 in 2025 to a central estimate of 5.3 (95% range 2.9–7.8). A 5-year backtest shows a typical error of ±37.4%, with 100% of held-out values landing inside the 95% band.

+47%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 →
5.3Projected 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 →
2.9–7.895% 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 →
±37.4%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, Black-throated Gray Warbler in Sierra Nevada is projected to rise about 47% by 2030 — from 3.6 in 2025 to a central estimate of 5.3 (95% range 2.9–7.8). A 5-year backtest shows a typical error of ±37.4%, with 100% of held-out values landing inside the 95% band.19692030
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 →
20265.12.77.6
20275.22.77.7
20285.22.87.7
20295.32.87.7
20305.32.97.8

Routes In Sierra Nevada

Routes recording Black-throated Gray 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 2CALIFORNIA332005
RivertonCALIFORNIA142025
Forest HillCALIFORNIA142025
PlacervilleCALIFORNIA122025
Silver CityCALIFORNIA112013
Butte MeadowCALIFORNIA112014
StrawberryCALIFORNIA102019
LumberyardCALIFORNIA82025
GeneseeCALIFORNIA82024
LakeshoreCALIFORNIA62009
DardanelleCALIFORNIA52019
Tuolumne GroveCALIFORNIA52025
WestvilleCALIFORNIA32025
SattleyCALIFORNIA31996
WawonaCALIFORNIA32024
Last ChanceCALIFORNIA32018
Bass LakeCALIFORNIA22018
JohnsvilleCALIFORNIA22025
Kings CanyonCALIFORNIA22024
Higgins CornCALIFORNIA22025
DownievilleCALIFORNIA22025
Eagle LakeCALIFORNIA12025
Cottage SpgsCALIFORNIA11974
Greenhorn MtCALIFORNIA11988
Hat CreekCALIFORNIA12006

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