BirdAnalyst
Species · Washington · BBS 2026 Release · 1966–2025

Northern Waterthrush Population Trend in Washington

All statesForest birds

Northern Waterthrush in Washington has surged: up 99% on the route-weighted index since 1989.

+99%Since 1989TrendPercent 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 →
7Routes 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 →
37YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Northern Waterthrush 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 Northern Waterthrush in Washington. See the full index history below.

Northern Waterthrush Population Forecast in Washington

If the recent trend holds, Northern Waterthrush in Washington is projected to fall about 26% by 2030 — from 0.06 in 2025 to a central estimate of 0.05 (95% range 0.00–0.15). A 5-year backtest shows a typical error of ±117.4%, with 100% of held-out values landing inside the 95% band.

-26%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 →
0.05Projected 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 →
0.00–0.1595% 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 →
±117.4%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, Northern Waterthrush in Washington is projected to fall about 26% by 2030 — from 0.06 in 2025 to a central estimate of 0.05 (95% range 0.00–0.15). A 5-year backtest shows a typical error of ±117.4%, with 100% of held-out values landing inside the 95% band.19822030
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 →
20260.050.000.16
20270.050.000.15
20280.050.000.15
20290.050.000.15
20300.050.000.15

Northern Waterthrush Survey Routes in Washington

Routes recording Northern Waterthrush 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 →
Sullivan Lk719991999
Cusick320251982
Sullivan Lake 2320232001
Omak Creek120101996
Northport120071999
L Pend O Nwr120231999
Curlew120131993

Northern Waterthrush Population Trend in Other States

alaskaconnecticutidahomainemarylandmassachusettsmichiganminnesotamontananew-hampshirenew-jerseynew-yorknorth-carolinanorth-dakotaohiopennsylvaniarhode-islandvermontvirginiawest-virginiawisconsinwyoming

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