BirdAnalyst
Species · BCR 15 · BBS 2026 Release · 1966–2025

Red Crossbill In Sierra Nevada

All regionsSierra NevadaForest birds

Red Crossbill in Sierra Nevada has surged: up 78% on the route-weighted index since 1971.

+78%Since 1971TrendPercent 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 →
26Routes In RegionSurvey 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 SignalsNotable 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 Sierra Nevada: up 78% on the route-weighted index since 1971.

Red Crossbill In Sierra Nevada Population Forecast

If the recent trend holds, Red Crossbill in Sierra Nevada is projected to fall about 75% by 2030 — from 4.8 in 2025 to a central estimate of 1.2 (95% range 0.00–3.8). A 5-year backtest shows a typical error of ±38.7%, with 80% of held-out values landing inside the 95% band.

-75%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 →
1.2Projected 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 →
0.00–3.895% 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 →
±38.7%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, Red Crossbill in Sierra Nevada is projected to fall about 75% by 2030 — from 4.8 in 2025 to a central estimate of 1.2 (95% range 0.00–3.8). A 5-year backtest shows a typical error of ±38.7%, with 80% of held-out values landing inside the 95% band.19692030
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 →
20261.20.003.8
20271.20.003.8
20281.20.003.8
20291.20.003.8
20301.20.003.8

Routes In Sierra Nevada

Routes recording Red Crossbill in Sierra Nevada.
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 →
Eagle LakeCALIFORNIA402025
WestvilleCALIFORNIA232025
CrestviewCALIFORNIA162025
Little TruckeeCALIFORNIA112023
ChilcootCALIFORNIA112024
StrawberryCALIFORNIA82001
Greenhorn MtCALIFORNIA51996
Tuolumne GroveCALIFORNIA52025
CoultervilleCALIFORNIA52002
LumberyardCALIFORNIA32012
GeneseeCALIFORNIA32014
GoumazCALIFORNIA32011
Forest HillCALIFORNIA32002
Last ChanceCALIFORNIA32016
Butte MeadowCALIFORNIA22014
RivertonCALIFORNIA22007
Hat CreekCALIFORNIA22018
LakeshoreCALIFORNIA22002
Tahoe NfCALIFORNIA21994
Chaos CraterCALIFORNIA22007
Pollock PinesCALIFORNIA22025
DardanelleCALIFORNIA12013
WoodfordsCALIFORNIA12019
DownievilleCALIFORNIA12024
WawonaCALIFORNIA12008

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