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Species · Idaho · BBS 2026 Release · 1966–2025

White-crowned Sparrow Population Trend in Idaho

All statesForest birds

White-crowned Sparrow in Idaho has edged down: down 21% on the route-weighted index since 1971.

-21%Since 1971TrendPercent 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 →
56YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable White-crowned Sparrow 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 White-crowned Sparrow in Idaho. See the full index history below.

White-crowned Sparrow Population Forecast in Idaho

If the recent trend holds, White-crowned Sparrow in Idaho is projected to stay roughly flat through 2030, near 1.2 (95% range 0.23–2.2). A 5-year backtest shows a typical error of ±15.8%, with 100% of held-out values landing inside the 95% band.

-2%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 →
1.2Projected 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 →
0.23–2.295% 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 →
±15.8%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, White-crowned Sparrow in Idaho is projected to stay roughly flat through 2030, near 1.2 (95% range 0.23–2.2). A 5-year backtest shows a typical error of ±15.8%, 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 →
20261.20.212.1
20271.20.222.1
20281.20.222.2
20291.20.232.2
20301.20.232.2

White-crowned Sparrow Survey Routes in Idaho

Routes recording White-crowned Sparrow 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 →
Cape Horn2420251972
Golden2320112011
Alturas1919871968
Avery720031979
Challis520251975
Leadore520241974
Sunbeam520251994
Dubois419701970
Magic Mtn420251987
Featherville419961995
Lolo Pass320151995
Coolin319951995
Marble Creek319981998
Crane Creek320032003
Sawtooth Cty320141988
Nezperce219921992
Cascade219841971
Squirrel220241971
Blacks Creek219811981
Henry219811973
Sawtooth City 2220252015
Burgdorf220251988
Yellow Pine220111995
Iron Springs220192012
Mud Lake220002000

White-crowned Sparrow Population Trend in Other States

alaskacaliforniacoloradomontananevadanew-mexicooregonutahwashingtonwyoming

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