BirdAnalyst
Species · Idaho · BBS 2026 Release · 1966–2025

Red Crossbill Population Trend in Idaho

All statesForest birds

Red Crossbill in Idaho has surged: up 323% on the route-weighted index since 1976.

+323%Since 1976TrendPercent 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 →
33Routes 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 →
51YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Red Crossbill 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 →

Red Crossbill has surged in Idaho: up 323% on the route-weighted index since 1976.

Red Crossbill Population Forecast in Idaho

If the recent trend holds, Red Crossbill in Idaho is projected to fall about 31% by 2030 — from 2.4 in 2025 to a central estimate of 1.7 (95% range 0.00–4.1). A 5-year backtest shows a typical error of ±74.1%, with 100% of held-out values landing inside the 95% band.

-31%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 →
1.7Projected 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 →
0.00–4.195% 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 →
±74.1%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, Red Crossbill in Idaho is projected to fall about 31% by 2030 — from 2.4 in 2025 to a central estimate of 1.7 (95% range 0.00–4.1). A 5-year backtest shows a typical error of ±74.1%, with 100% of held-out values landing inside the 95% band.19712030
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 →
20261.70.004.1
20271.70.004.1
20281.70.004.1
20291.70.004.1
20301.70.004.1

Red Crossbill Survey Routes in Idaho

Routes recording Red Crossbill 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 →
Coolin3820251986
Triangle1420212010
Naples1020251972
Centerville1020251982
Sunbeam1020171995
Rochat Divde920241993
Alturas919861986
Featherville920251989
Baldy Mountain720152013
Cascade619841983
Silver City620122012
Nezperce519941985
Golden420081994
Nezperce Nf419921992
Cabarton420231985
Mivoden320251977
Lolo Pass320191993
Grangeville320251986
Cape Horn320251986
Squirrel320071971
Marble Creek320251990
Avery220251979
Gifford220111986
Challis220191976
Pierce220051990

Red Crossbill Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradogeorgiaillinoismainemarylandmassachusettsmichiganminnesotamontananebraskanevadanew-hampshirenew-mexiconew-yorknorth-carolinanorth-dakotaoregonpennsylvaniasouth-carolinasouth-dakotatennesseeutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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