BirdAnalyst
Species · BCR 15 · BBS 2025 Release · 1966–2024

Pine Siskin In Sierra Nevada

All regionsSierra NevadaGeneralists

Pine Siskin in Sierra Nevada has collapsed: down 82% on the route-weighted index since 1973.

-82%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 →
53YearsYears 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 collapsed in Sierra Nevada: down 82% 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 18% by 2029 — from 0.74 in 2024 to a central estimate of 0.61 (95% range 0.00–2.6). A 5-year backtest shows a typical error of ±211.6%, with 100% of held-out values landing inside the 95% band.

-18%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 →
0.61Projected 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 →
0.00–2.695% 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 →
±211.6%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 18% by 2029 — from 0.74 in 2024 to a central estimate of 0.61 (95% range 0.00–2.6). A 5-year backtest shows a typical error of ±211.6%, with 100% 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 →
20250.710.002.7
20260.690.002.7
20270.660.002.7
20280.630.002.7
20290.610.002.6

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 →
LakeshoreCALIFORNIA102005
Little TruckeeCALIFORNIA92022
Tuolumne GroveCALIFORNIA72011
Bass LakeCALIFORNIA62011
Butte MeadowCALIFORNIA62013
Meadow ValleyCALIFORNIA62018
Lassen ParkCALIFORNIA51987
Tahoe NfCALIFORNIA51994
ChesterCALIFORNIA52017
Pine MountainCALIFORNIA52009
ChilcootCALIFORNIA52024
Last ChanceCALIFORNIA52019
DardanelleCALIFORNIA42018
JohnsvilleCALIFORNIA42024
WoodfordsCALIFORNIA42024
GeneseeCALIFORNIA42011
Eagle LakeCALIFORNIA31993
CrestviewCALIFORNIA32018
WestvilleCALIFORNIA22016
Cottage SpgsCALIFORNIA21974
RivertonCALIFORNIA22016
Forest HillCALIFORNIA22017
Pollock PinesCALIFORNIA22016
LumberyardCALIFORNIA12018
Greenhorn MtCALIFORNIA11977

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