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

Horned Lark In Sierra Nevada

All regionsSierra NevadaGrassland birds

Horned Lark in Sierra Nevada has collapsed: down 77% on the route-weighted index since 1971.

-77%Since 1971TrendPercent 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 →
8Routes 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 →

Horned Lark has collapsed in Sierra Nevada: down 77% on the route-weighted index since 1971.

Horned Lark In Sierra Nevada Population Forecast

If the recent trend holds, Horned Lark in Sierra Nevada is projected to rise about 235% by 2030 — from 0.39 in 2025 to a central estimate of 1.3 (95% range 0.00–4.1). A 5-year backtest shows a typical error of ±580.3%, with 100% of held-out values landing inside the 95% band.

+235%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 →
1.3Projected 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 →
0.00–4.195% 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 →
±580.3%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, Horned Lark in Sierra Nevada is projected to rise about 235% by 2030 — from 0.39 in 2025 to a central estimate of 1.3 (95% range 0.00–4.1). A 5-year backtest shows a typical error of ±580.3%, with 100% of held-out values landing inside the 95% band.19692030
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 →
20261.40.004.2
20271.40.004.2
20281.40.004.2
20291.30.004.1
20301.30.004.1

Routes In Sierra Nevada

Routes recording Horned Lark 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 →
GoumazCALIFORNIA512011
Eagle LakeCALIFORNIA82024
SattleyCALIFORNIA72025
ChilcootCALIFORNIA41998
GeneseeCALIFORNIA31978
Last ChanceCALIFORNIA32019
DardanelleCALIFORNIA11997
Little TruckeeCALIFORNIA12021

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