BirdAnalyst
Species · West Virginia · BBS 2025 Release · 1966–2024

Northern Waterthrush Population Trend in West Virginia

All statesForest birds

Northern Waterthrush in West Virginia has surged: up 149% on the route-weighted index since 1976.

+149%Since 1976TrendPercent 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 →
11Routes 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 →
33YearsYears 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 West VirginiaNotable 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 →

Northern Waterthrush has surged in West Virginia: up 149% on the route-weighted index since 1976.

Northern Waterthrush Population Forecast in West Virginia

If the recent trend holds, Northern Waterthrush in West Virginia is projected to fall about 64% by 2029 — from 0.27 in 2024 to a central estimate of 0.10 (95% range 0.00–0.20). A 5-year backtest shows a typical error of ±67.9%, with 60% of held-out values landing inside the 95% band.

-64%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 →
0.10Projected 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 →
0.00–0.2095% 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 →
±67.9%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, Northern Waterthrush in West Virginia is projected to fall about 64% by 2029 — from 0.27 in 2024 to a central estimate of 0.10 (95% range 0.00–0.20). A 5-year backtest shows a typical error of ±67.9%, with 60% of held-out values landing inside the 95% band.19662029
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 →
20250.090.000.20
20260.090.000.20
20270.100.000.20
20280.100.000.20
20290.100.000.20

Northern Waterthrush Survey Routes in West Virginia

Routes recording Northern Waterthrush in West Virginia.
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 →
Glade Run 21020242004
Glady320232017
Dailey220222022
Mo Of Seneca119991999
Glade Run120021988
Meadowville119731973
Canaan119811976
Valley Head120061966
Three Forks119991999
Denmar120071994
Green Bank119861986

Northern Waterthrush Population Trend in Other States

alaskaconnecticutidahomainemarylandmassachusettsmichiganminnesotamontananew-hampshirenew-jerseynew-yorknorth-carolinanorth-dakotaohiopennsylvaniarhode-islandvermontvirginiawashingtonwisconsinwyoming

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