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Species · Idaho · BBS 2026 Release · 1966–2025

Cassin's Finch Population Trend in Idaho

All statesForest birds

Cassin's Finch in Idaho has surged: up 528% on the route-weighted index since 1972.

+528%Since 1972TrendPercent 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 →
44Routes 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 →
55YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Cassin's Finch 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 →

Cassin's Finch has surged in Idaho: up 528% on the route-weighted index since 1972.

Cassin's Finch Population Forecast in Idaho

If the recent trend holds, Cassin's Finch in Idaho is projected to rise about 90% by 2030 — from 1.7 in 2025 to a central estimate of 3.1 (95% range 1.2–5.1). A 5-year backtest shows a typical error of ±152.7%, with 0% of held-out values landing inside the 95% band.

+90%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 →
3.1Projected 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 →
1.2–5.195% 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 →
±152.7%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, Cassin's Finch in Idaho is projected to rise about 90% by 2030 — from 1.7 in 2025 to a central estimate of 3.1 (95% range 1.2–5.1). A 5-year backtest shows a typical error of ±152.7%, with 0% 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 →
20263.01.05.0
20273.01.15.0
20283.11.15.1
20293.11.15.1
20303.11.25.1

Cassin's Finch Survey Routes in Idaho

Routes recording Cassin's Finch 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 →
Magic Mtn1420251987
Yellow Pine1320161989
Silver City1120251989
Cascade819841974
Coolin720251986
Almo720231988
Deep Creek619851985
Cape Horn620251987
Bates620131992
Rochat Divde520231994
Sunbeam520191994
Picabo520031997
Nezperce Nf519921992
Centerville420251972
Alturas419871968
Marble Creek420251990
Dougal Res420191990
Leadore320191979
Burgdorf320251988
Sawtooth Cty320141989
Mivoden220071978
Avery220251979
Gifford220101986
Grangeville220251986
Golden220071987

Cassin's Finch Population Trend in Other States

arizonacaliforniacoloradomontananevadanew-mexicooregonsouth-dakotautahwashingtonwyoming

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