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

Wilson's Warbler Population Trend in Idaho

All statesForest birds

Wilson's Warbler in Idaho has surged: up 279% on the route-weighted index since 1975.

+279%Since 1975TrendPercent 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 →
38Routes 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 →
51YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Wilson's Warbler Trends in IdahoNotable 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 →

Wilson's Warbler has surged in Idaho: up 279% on the route-weighted index since 1975.

Wilson's Warbler Population Forecast in Idaho

If the recent trend holds, Wilson's Warbler in Idaho is projected to stay roughly flat through 2030, near 0.43 (95% range 0.00–0.94). A 5-year backtest shows a typical error of ±80.3%, with 100% of held-out values landing inside the 95% band.

-6%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 →
0.43Projected 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 →
0.00–0.9495% 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 →
±80.3%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, Wilson's Warbler in Idaho is projected to stay roughly flat through 2030, near 0.43 (95% range 0.00–0.94). A 5-year backtest shows a typical error of ±80.3%, with 100% of held-out values landing inside the 95% band.19682030
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 →
20260.430.000.94
20270.430.000.94
20280.430.000.94
20290.430.000.94
20300.430.000.94

Wilson's Warbler Survey Routes in Idaho

Routes recording Wilson's Warbler in Idaho.
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 →
Lolo Pass1220191993
Avery520251979
Mivoden420251977
Marble Creek420251988
Naples220211996
Squirrel219771977
Coolin220251992
Baldy Mountain220152013
Yellow Pine219911991
Featherville220161990
Picabo220132013
Gifford119931971
Nezperce120071968
Golden120081987
Baker120132011
Cascade119841984
Cape Horn120211998
Challis120231979
Leadore120241975
N Fork Cda R120171993
Rochat Divde120191993
Centerville120251983
Triangle119951995
Magic Mtn120051987
Acequia119891989

Wilson's Warbler Population Trend in Other States

alaskacaliforniacoloradomainemichiganminnesotamontananevadanew-hampshirenew-mexiconew-yorkoregonutahvermontwashingtonwisconsinwyoming

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