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

Pine Siskin In Sierra Nevada

All regionsSierra NevadaForest birds

Pine Siskin in Sierra Nevada has fallen sharply: down 73% on the route-weighted index since 1973.

-73%Since 1973TrendPercent 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 →
37Routes 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 declinecomputed 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 →

Pine Siskin has fallen sharply in Sierra Nevada: down 73% on the route-weighted index since 1973.

Pine Siskin In Sierra Nevada Population Forecast

If the recent trend holds, Pine Siskin in Sierra Nevada is projected to fall about 54% by 2030 — from 1.4 in 2025 to a central estimate of 0.64 (95% range 0.00–2.7). A 5-year backtest shows a typical error of ±151.2%, with 100% of held-out values landing inside the 95% band.

-54%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 →
0.64Projected 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 →
0.00–2.795% 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 →
±151.2%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, Pine Siskin in Sierra Nevada is projected to fall about 54% by 2030 — from 1.4 in 2025 to a central estimate of 0.64 (95% range 0.00–2.7). A 5-year backtest shows a typical error of ±151.2%, 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 →
20260.740.002.8
20270.710.002.7
20280.690.002.7
20290.660.002.7
20300.640.002.7

Routes In Sierra Nevada

Routes recording Pine Siskin 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 →
CrestviewCALIFORNIA112025
LakeshoreCALIFORNIA102005
Tuolumne GroveCALIFORNIA72011
Bass LakeCALIFORNIA62011
Butte MeadowCALIFORNIA62013
Meadow ValleyCALIFORNIA62018
Lassen ParkCALIFORNIA51987
Tahoe NfCALIFORNIA51994
ChesterCALIFORNIA52017
Pine MountainCALIFORNIA52009
ChilcootCALIFORNIA52024
Last ChanceCALIFORNIA52019
DardanelleCALIFORNIA42018
JohnsvilleCALIFORNIA42024
LumberyardCALIFORNIA42025
GeneseeCALIFORNIA42011
Eagle LakeCALIFORNIA31993
SattleyCALIFORNIA32025
WestvilleCALIFORNIA22025
Cottage SpgsCALIFORNIA21974
WoodfordsCALIFORNIA22025
Little TruckeeCALIFORNIA22025
Forest HillCALIFORNIA22017
Pollock PinesCALIFORNIA22016
Greenhorn MtCALIFORNIA11977

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