BirdAnalyst
Species · BCR 33 · BBS 2025 Release · 1966–2024

Horned Lark In Sonoran and Mojave Deserts

All regionsSonoran and Mojave DesertsGrassland birds

Horned Lark in Sonoran and Mojave Deserts has fallen sharply: down 53% on the route-weighted index since 1970.

-53%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 →
81Routes 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 →
56YearsYears 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 fallen sharply in Sonoran and Mojave Deserts: down 53% on the route-weighted index since 1970.

Forecast

If the recent trend holds, Horned Lark in Sonoran and Mojave Deserts is projected to fall about 52% by 2029 — from 12 in 2024 to a central estimate of 5.8 (95% range 0.00–19). A 5-year backtest shows a typical error of ±30.5%, with 100% of held-out values landing inside the 95% band.

-52%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 →
5.8Projected 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 →
0.00–1995% 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 →
±30.5%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 Sonoran and Mojave Deserts is projected to fall about 52% by 2029 — from 12 in 2024 to a central estimate of 5.8 (95% range 0.00–19). A 5-year backtest shows a typical error of ±30.5%, with 100% of held-out values landing inside the 95% band.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 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 →
20257.10.0020
20266.80.0020
20276.50.0020
20286.20.0019
20295.80.0019

Routes In Sonoran and Mojave Deserts

Routes recording Horned Lark in Sonoran and Mojave Deserts.
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 →
Lane MtnCALIFORNIA1751973
Willow SpgsCALIFORNIA1291981
BarstowCALIFORNIA1221998
LenwoodCALIFORNIA802012
Silver Peak 2NEVADA702024
Calif CityCALIFORNIA632015
CoolidgeARIZONA581985
BeattyNEVADA582024
InyokernCALIFORNIA452024
Greenwater VCALIFORNIA332024
Silver PeakNEVADA312006
Lucerne ValCALIFORNIA252024
WildroseCALIFORNIA232022
Palo VerdeCALIFORNIA232024
Ft IrwinCALIFORNIA201982
AntaresARIZONA192024
Palo VerdeARIZONA182013
LagunaARIZONA172023
Hope 2ARIZONA162018
Willow Springs 2CALIFORNIA162024
NelsonNEVADA162022
Palo Verde 2ARIZONA152024
Casa GrandeARIZONA142023
Iron MtnsCALIFORNIA142019
Alamo RiverCALIFORNIA132018

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