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

Cassin's Finch Population Trend in Idaho

All statesGeneralists

Cassin's Finch in Idaho has surged: up 507% on the route-weighted index since 1972.

+507%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 →
54YearsYears 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 507% 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 120% by 2029 — from 1.5 in 2024 to a central estimate of 3.3 (95% range 1.3–5.2). A 5-year backtest shows a typical error of ±130.6%, with 20% of held-out values landing inside the 95% band.

+120%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 →
3.3Projected 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 →
1.3–5.295% 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 →
±130.6%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, Cassin's Finch in Idaho is projected to rise about 120% by 2029 — from 1.5 in 2024 to a central estimate of 3.3 (95% range 1.3–5.2). A 5-year backtest shows a typical error of ±130.6%, with 20% of held-out values landing inside the 95% band.19682029
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 →
20253.11.15.1
20263.11.25.1
20273.21.25.1
20283.21.35.2
20293.31.35.2

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 →
Silver City1720241989
Yellow Pine1320161989
Centerville1120191972
Cascade819841974
Cape Horn820241987
Burgdorf820161988
Almo720231988
Deep Creek619851985
Bates620131992
Rochat Divde520231994
Sunbeam520191994
Picabo520031997
Nezperce Nf519921992
Avery420231979
Alturas419871968
Dougal Res420191990
Cabarton420231985
Challis320241978
Leadore320191979
Sawtooth Cty320141989
Mivoden220071978
Gifford220101986
Grangeville220221986
Golden220071987
N Fork Cda R220012001

Cassin's Finch Population Trend in Other States

arizonacaliforniacoloradomontananevadanew-mexicooregonsouth-dakotautahwashingtonwyoming

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