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

Red Crossbill Population Trend in Idaho

All statesGeneralists

Red Crossbill in Idaho has surged: up 352% on the route-weighted index since 1976.

+352%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 →
50YearsYears 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 352% 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 rise about 571% by 2029 — from 0.24 in 2024 to a central estimate of 1.6 (95% range 0.00–4.1). A 5-year backtest shows a typical error of ±127.8%, with 80% of held-out values landing inside the 95% band.

+571%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 →
1.6Projected 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 →
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 →
±127.8%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, Red Crossbill in Idaho is projected to rise about 571% by 2029 — from 0.24 in 2024 to a central estimate of 1.6 (95% range 0.00–4.1). A 5-year backtest shows a typical error of ±127.8%, with 80% of held-out values landing inside the 95% band.19712029
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 →
20251.60.004.1
20261.60.004.1
20271.60.004.1
20281.60.004.1
20291.60.004.1

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 →
Coolin4820231986
Rochat Divde4220231993
Triangle1420212010
Sunbeam1020171995
Avery920231979
Alturas919861986
Mivoden820231977
Baldy Mountain720152013
Cascade619841983
Silver City620122012
Nezperce519941985
Cape Horn520231986
Grangeville420241986
Golden420081994
Centerville420191982
Nezperce Nf419921992
Cabarton420231985
Naples320221972
Lolo Pass320191993
Squirrel320071971
Marble Creek320231990
Gifford220111986
Challis220191976
Pierce220051990
Yellow Pine220161989

Red Crossbill Population Trend in Other States

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

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