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Species · Montana · BBS 2026 Release · 1966–2025

Cassin's Finch Population Trend in Montana

All statesForest birds

Cassin's Finch in Montana has increased: up 37% on the route-weighted index since 1970.

+37%Since 1970TrendPercent 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 →
43Routes 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 →
57YearsYears 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 MontanaNotable 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 Cassin's Finch in Montana. See the full index history below.

Cassin's Finch Population Forecast in Montana

If the recent trend holds, Cassin's Finch in Montana is projected to rise about 108% by 2030 — from 0.20 in 2025 to a central estimate of 0.43 (95% range 0.00–1.3). A 5-year backtest shows a typical error of ±165%, with 100% of held-out values landing inside the 95% band.

+108%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 →
0.00–1.395% 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 →
±165%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 Montana is projected to rise about 108% by 2030 — from 0.20 in 2025 to a central estimate of 0.43 (95% range 0.00–1.3). A 5-year backtest shows a typical error of ±165%, 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 →
20260.440.001.3
20270.430.001.3
20280.430.001.3
20290.430.001.3
20300.430.001.3

Cassin's Finch Survey Routes in Montana

Routes recording Cassin's Finch in Montana.
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 →
Greenoagh 2620112009
Sula420241977
Clancy420172015
Libby Dam319941979
Logan Pass319921980
Victor320161993
St Regis320251978
Arlee320151972
Clinton320251976
Chestnut320241968
East Glacier Park320182018
Thompson Riv320221993
Fish Creek320241997
Kalispell220221970
Greenough220031995
Elevation Mt220252003
Pryor Mtn.220191995
Polson220251989
Augusta219991994
Savage219961996
Reed Point220151977
Whitefish Lake220222021
Greenoagh 3220252015
Hebgen Lake220252017
Painted Rock220221992

Cassin's Finch Population Trend in Other States

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