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

Lark Sparrow In Sierra Nevada

All regionsSierra NevadaGrassland birds

Lark Sparrow in Sierra Nevada has fallen sharply: down 60% on the route-weighted index since 1973.

-60%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 →
19Routes 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 →
47YearsYears 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 →

Lark Sparrow has fallen sharply in Sierra Nevada: down 60% on the route-weighted index since 1973.

Lark Sparrow In Sierra Nevada Population Forecast

If the recent trend holds, Lark Sparrow in Sierra Nevada is projected to fall about 100% by 2030 — from 0.39 in 2025 to a central estimate of 0.00 (95% range 0.00–0.60). A 5-year backtest shows a typical error of ±148.1%, with 100% of held-out values landing inside the 95% band.

-100%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 →
0.00Projected 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 →
0.00–0.6095% 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 →
±148.1%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, Lark Sparrow in Sierra Nevada is projected to fall about 100% by 2030 — from 0.39 in 2025 to a central estimate of 0.00 (95% range 0.00–0.60). A 5-year backtest shows a typical error of ±148.1%, 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 →
20260.000.000.60
20270.000.000.60
20280.000.000.60
20290.000.000.60
20300.000.000.60

Routes In Sierra Nevada

Routes recording Lark 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 →
LumberyardCALIFORNIA71988
SattleyCALIFORNIA72012
Eagle LakeCALIFORNIA62025
Silver CityCALIFORNIA42004
Kings CanyonCALIFORNIA31984
Higgins CornCALIFORNIA32002
Last ChanceCALIFORNIA32019
Cottage SpgsCALIFORNIA21975
Greenhorn MtCALIFORNIA22008
GeneseeCALIFORNIA21979
Pollock PinesCALIFORNIA22024
Bass LakeCALIFORNIA12008
WoodfordsCALIFORNIA12025
Tuolumne GroveCALIFORNIA12018
RivertonCALIFORNIA12017
PlacervilleCALIFORNIA12024
CoultervilleCALIFORNIA12018
WawonaCALIFORNIA12024
Pine MountainCALIFORNIA12016

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