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

Western Bluebird Population Trend in Idaho

All statesForest birds

Western Bluebird in Idaho has edged down: down 21% on the route-weighted index since 1984.

-21%Since 1984TrendPercent 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 →
13Routes 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 →
30YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Western Bluebird 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 →

No notable trend signals for Western Bluebird in Idaho. See the full index history below.

Western Bluebird Population Forecast in Idaho

If the recent trend holds, Western Bluebird in Idaho is projected to fall about 73% by 2029 — from 0.32 in 2024 to a central estimate of 0.09 (95% range 0.00–0.34). A 5-year backtest shows a typical error of ±79.6%, with 60% of held-out values landing inside the 95% band.

-73%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 →
0.09Projected 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 →
0.00–0.3495% 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 →
±79.6%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, Western Bluebird in Idaho is projected to fall about 73% by 2029 — from 0.32 in 2024 to a central estimate of 0.09 (95% range 0.00–0.34). A 5-year backtest shows a typical error of ±79.6%, with 60% of held-out values landing inside the 95% band.19722029
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 →
20250.090.000.34
20260.090.000.34
20270.090.000.34
20280.090.000.34
20290.090.000.34

Western Bluebird Survey Routes in Idaho

Routes recording Western Bluebird 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 →
Grangeville919861986
Gifford420162010
Joel420241991
Burgdorf319881988
Cascade219841984
Rochat Divde220162016
Salmon River220031998
Squirrel219861986
Featherville220241990
Coolin220242022
Naples120231997
Cape Horn119721972
Centerville120081982

Western Bluebird Population Trend in Other States

arizonacaliforniacoloradomontananevadanew-mexicooregontexasutahwashingtonwyoming

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