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

Lark Sparrow In Sonoran and Mojave Deserts

All regionsSonoran and Mojave DesertsGrassland birds

Lark Sparrow in Sonoran and Mojave Deserts has risen sharply: up 54% on the route-weighted index since 1970.

+54%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 →
43Routes 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 increasecomputed 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 risen sharply in Sonoran and Mojave Deserts: up 54% on the route-weighted index since 1970.

Lark Sparrow In Sonoran and Mojave Deserts Population Forecast

If the recent trend holds, Lark Sparrow in Sonoran and Mojave Deserts is projected to rise about 45% by 2029 — from 0.23 in 2024 to a central estimate of 0.34 (95% range 0.00–0.82). A 5-year backtest shows a typical error of ±163.7%, with 100% of held-out values landing inside the 95% band.

+45%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 →
0.34Projected 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 →
0.00–0.8295% 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 →
±163.7%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 Sonoran and Mojave Deserts is projected to rise about 45% by 2029 — from 0.23 in 2024 to a central estimate of 0.34 (95% range 0.00–0.82). A 5-year backtest shows a typical error of ±163.7%, 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 →
20250.330.000.82
20260.330.000.82
20270.340.000.82
20280.340.000.82
20290.340.000.82

Routes In Sonoran and Mojave Deserts

Routes recording Lark Sparrow 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 →
OnyxCALIFORNIA162015
FlorenceARIZONA81975
Lone PineCALIFORNIA71998
Greenwater VCALIFORNIA71998
Palo VerdeARIZONA62013
DatelandARIZONA52016
Cactus ForestARIZONA42019
Red Rock 2ARIZONA32023
BarstowCALIFORNIA31973
CimaCALIFORNIA31971
Willow Springs 2CALIFORNIA32024
OatmanARIZONA22006
HopeARIZONA22004
Cutter 2ARIZONA22018
Palo VerdeCALIFORNIA22015
Anza BorregoCALIFORNIA21998
BlytheCALIFORNIA21979
Alamo RiverCALIFORNIA22018
Ft IrwinCALIFORNIA21975
Kelso ValleyCALIFORNIA22024
Joshua TreeCALIFORNIA21995
Jean LakeNEVADA22008
Squaw PeakARIZONA11969
QuartzsiteARIZONA11992
LagunaARIZONA11978

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