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

Fox Sparrow In Sierra Nevada

All regionsSierra NevadaGeneralists

Fox Sparrow in Sierra Nevada has surged: up 191% on the route-weighted index since 1970.

+191%Since 1970
38Routes In Region
56Years

Notable Signals

long arc increasecomputed index

Fox Sparrow has surged in Sierra Nevada: up 191% on the route-weighted index since 1970.

Forecast

If the recent trend holds, Fox Sparrow in Sierra Nevada is projected to rise about 23% by 2029 — from 9.4 in 2024 to a central estimate of 12 (95% range 3.0–20). A 5-year backtest shows a typical error of ±29.3%, with 100% of held-out values landing inside the 95% band.

+23%Change by 2029
12Projected 2029 index
3.0–2095% range
±29.3%Backtest error
19682029
Projection of the recent trend (dashed) with 80/95% bands — a projection, not a prediction. Habitat, climate, and land use are not modeled.
YearProjected index95% low95% high
2025123.120
2026123.120
2027123.120
2028123.120
2029123.020

Routes In Sierra Nevada

Routes recording Fox Sparrow in Sierra Nevada.
WestvilleCALIFORNIA482024
Tahoe NfCALIFORNIA401994
Greenhorn MtCALIFORNIA322008
JohnsvilleCALIFORNIA292024
GeneseeCALIFORNIA292024
Pine MountainCALIFORNIA252017
Cottage SpgsCALIFORNIA201975
LakeshoreCALIFORNIA202024
Tuolumne GroveCALIFORNIA152024
ChesterCALIFORNIA132017
Meadow ValleyCALIFORNIA122024
Little TruckeeCALIFORNIA122023
DardanelleCALIFORNIA112019
Lassen ParkCALIFORNIA81989
Hat CreekCALIFORNIA82018
LumberyardCALIFORNIA72024
Butte MeadowCALIFORNIA72014
Pollock PinesCALIFORNIA72024
DownievilleCALIFORNIA62024
CoultervilleCALIFORNIA62019
Last ChanceCALIFORNIA62019
Chaos CraterCALIFORNIA52019
Silver CityCALIFORNIA42013
RivertonCALIFORNIA42023
WoodfordsCALIFORNIA22024

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