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

Canada Warbler Population Trend in West Virginia

All statesForest birds

Canada Warbler in West Virginia has surged: up 12× on the route-weighted index since 1978.

12×Since 1978TrendPercent 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 →
18Routes 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 →
48YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Canada Warbler 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 →

Canada Warbler has surged in West Virginia: up 12× on the route-weighted index since 1978.

Canada Warbler Population Forecast in West Virginia

If the recent trend holds, Canada Warbler in West Virginia is projected to fall about 38% by 2029 — from 0.62 in 2024 to a central estimate of 0.39 (95% range 0.04–0.73). A 5-year backtest shows a typical error of ±54%, with 100% of held-out values landing inside the 95% band.

-38%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 →
0.39Projected 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 →
0.04–0.7395% 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 →
±54%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, Canada Warbler in West Virginia is projected to fall about 38% by 2029 — from 0.62 in 2024 to a central estimate of 0.39 (95% range 0.04–0.73). A 5-year backtest shows a typical error of ±54%, with 100% of held-out values landing inside the 95% band.19702029
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 →
20250.380.040.72
20260.380.040.72
20270.380.040.72
20280.380.040.72
20290.390.040.73

Canada Warbler Survey Routes in West Virginia

Routes recording Canada Warbler 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 21020242003
Richwood620241980
Glady420242005
Glade Run320021988
Bemis320242004
Dailey220191975
Bowden120231993
Wymer120081996
Clear Creek119921992
Albright119701970
Meadowville120121991
Sleepy Creek119821982
Bismark120211990
Canaan119941980
Valley Head119851985
Three Forks119871978
Denmar120161980
Green Bank119931979

Canada Warbler Population Trend in Other States

connecticutgeorgiaindianamainemarylandmassachusettsmichiganminnesotanew-hampshirenew-jerseynew-yorknorth-carolinaohiopennsylvaniarhode-islandtennesseevermontvirginiawisconsin

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