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

Chipping Sparrow In Sierra Nevada

All regionsSierra NevadaForest birds

Chipping Sparrow in Sierra Nevada has edged down: down 23% on the route-weighted index since 1970.

-23%Since 1970TrendPercent 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 →
39Routes 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 →
57YearsYears 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 →

No notable trend signals for Chipping Sparrow in Sierra Nevada. See the full index history below.

Chipping Sparrow In Sierra Nevada Population Forecast

If the recent trend holds, Chipping Sparrow in Sierra Nevada is projected to fall about 54% by 2030 — from 7.1 in 2025 to a central estimate of 3.3 (95% range 0.00–11). A 5-year backtest shows a typical error of ±52.2%, 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 →
3.3Projected 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 →
0.00–1195% 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 →
±52.2%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, Chipping Sparrow in Sierra Nevada is projected to fall about 54% by 2030 — from 7.1 in 2025 to a central estimate of 3.3 (95% range 0.00–11). A 5-year backtest shows a typical error of ±52.2%, with 100% of held-out values landing inside the 95% band.19682030
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 →
20263.90.0012
20273.70.0012
20283.60.0011
20293.40.0011
20303.30.0011

Routes In Sierra Nevada

Routes recording Chipping Sparrow 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 →
GoumazCALIFORNIA462011
ChesterCALIFORNIA252017
Eagle LakeCALIFORNIA222025
Last ChanceCALIFORNIA222019
WestvilleCALIFORNIA162025
Pollock PinesCALIFORNIA162025
ChilcootCALIFORNIA132024
RivertonCALIFORNIA122025
Tuolumne GroveCALIFORNIA112025
Pine MountainCALIFORNIA112017
Tahoe NfCALIFORNIA101994
Meadow ValleyCALIFORNIA102025
Little TruckeeCALIFORNIA92025
Cottage SpgsCALIFORNIA81975
DownievilleCALIFORNIA82022
CrestviewCALIFORNIA72025
LumberyardCALIFORNIA62025
JohnsvilleCALIFORNIA52025
Greenhorn MtCALIFORNIA52008
GeneseeCALIFORNIA52024
Forest HillCALIFORNIA52025
Hat CreekCALIFORNIA42018
PlacervilleCALIFORNIA42025
Lassen ParkCALIFORNIA31988
WoodfordsCALIFORNIA32025

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