BirdAnalyst
Species · BCR 34 · BBS 2026 Release · 1966–2025

Lark Sparrow In Sierra Madre Occidental

All regionsSierra Madre OccidentalGrassland birds

Lark Sparrow in Sierra Madre Occidental has edged down: down 17% on the route-weighted index since 1970.

-17%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 →
30Routes 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 →
57YearsYears 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 →

No notable trend signals for Lark Sparrow in Sierra Madre Occidental. See the full index history below.

Lark Sparrow In Sierra Madre Occidental Population Forecast

If the recent trend holds, Lark Sparrow in Sierra Madre Occidental is projected to rise about 35% by 2030 — from 2.2 in 2025 to a central estimate of 3.0 (95% range 0.45–5.5). A 5-year backtest shows a typical error of ±39.4%, with 100% of held-out values landing inside the 95% band.

+35%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 →
3.0Projected 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 →
0.45–5.595% 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 →
±39.4%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 Madre Occidental is projected to rise about 35% by 2030 — from 2.2 in 2025 to a central estimate of 3.0 (95% range 0.45–5.5). A 5-year backtest shows a typical error of ±39.4%, with 100% of held-out values landing inside the 95% band.19682030
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 →
20263.00.435.5
20273.00.435.5
20283.00.445.5
20293.00.445.5
20303.00.455.5

Routes In Sierra Madre Occidental

Routes recording Lark Sparrow in Sierra Madre Occidental.
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 →
Skull ValleyARIZONA222024
Skull Valley 2ARIZONA172025
Clay SpringARIZONA102025
Forest LakesARIZONA92025
DragoonARIZONA72009
Mormon LakeARIZONA61975
SunizonaARIZONA51997
MagdalenaNEW-MEXICO52025
FlagstaffARIZONA42025
San SimonARIZONA42001
SahuaritaARIZONA42021
WilliamsARIZONA32025
PomereneARIZONA22025
Peña BlancaARIZONA22005
PatagoniaARIZONA22025
CutterARIZONA22014
AmadoARIZONA22022
McnealARIZONA22009
ReserveNEW-MEXICO22025
Vicks PeakNEW-MEXICO22016
PrescottARIZONA12025
MaineARIZONA12025
PinetopARIZONA12022
AlpineARIZONA12025
RedingtonARIZONA12025

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