BirdAnalyst
Species · Washington · BBS 2025 Release · 1966–2024

Black-throated Gray Warbler Population Trend in Washington

All statesForest birds

Black-throated Gray Warbler in Washington has declined: down 36% on the route-weighted index since 1970.

-36%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 →
55Routes In StateSurvey 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 Black-throated Gray Warbler Trends in WashingtonNotable 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 Black-throated Gray Warbler in Washington. See the full index history below.

Black-throated Gray Warbler Population Forecast in Washington

If the recent trend holds, Black-throated Gray Warbler in Washington is projected to fall about 43% by 2029 — from 3.4 in 2024 to a central estimate of 1.9 (95% range 0.13–3.7). A 5-year backtest shows a typical error of ±45.9%, with 60% of held-out values landing inside the 95% band.

-43%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 →
1.9Projected 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 →
0.13–3.795% 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 →
±45.9%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, Black-throated Gray Warbler in Washington is projected to fall about 43% by 2029 — from 3.4 in 2024 to a central estimate of 1.9 (95% range 0.13–3.7). A 5-year backtest shows a typical error of ±45.9%, with 60% 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 →
20252.00.203.8
20262.00.183.8
20272.00.163.8
20282.00.153.8
20291.90.133.7

Black-throated Gray Warbler Survey Routes in Washington

Routes recording Black-throated Gray Warbler in Washington.
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 →
Cougar3320231969
Montesand2720241989
Index2019711968
Kendall2020241981
Raymond 21820242022
Newhalem1720241968
E. Mt. Adams1320241995
Neilton1319751975
Kamilche1220241968
Mt. Adams1120242002
Ozette1020241973
Glacier1020241977
Raymond920211993
Cedar Falls820141993
Packwood720241975
White Chuck620241992
Suiattle Riv620181993
Concrete620242013
Port Angeles520241972
South Elma520241975
Hurricane Rg520242003
Bunker Hill420241968
Snowden420241984
Rainier420181993
Greenwater420242015

Black-throated Gray Warbler Population Trend in Other States

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