BirdAnalyst
Species · BCR 34 · BBS 2025 Release · 1966–2024

Lark Sparrow In Sierra Madre Occidental

All regionsSierra Madre OccidentalGrassland birds

Lark Sparrow in Sierra Madre Occidental has edged down: down 12% on the route-weighted index since 1970.

-12%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 →
29Routes 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 →

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 stay roughly flat through 2029, near 3.0 (95% range 0.49–5.6). A 5-year backtest shows a typical error of ±48.1%, with 100% of held-out values landing inside the 95% band.

-9%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 →
3.0Projected 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 →
0.49–5.695% 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 →
±48.1%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 Madre Occidental is projected to stay roughly flat through 2029, near 3.0 (95% range 0.49–5.6). A 5-year backtest shows a typical error of ±48.1%, 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 →
20253.00.475.6
20263.00.475.6
20273.00.485.6
20283.00.485.6
20293.00.495.6

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
Clay SpringARIZONA172024
Forest LakesARIZONA92024
AlpineARIZONA82022
DragoonARIZONA72009
Mormon LakeARIZONA61975
Happy JackARIZONA62024
PatagoniaARIZONA52023
SunizonaARIZONA51997
San SimonARIZONA42001
SahuaritaARIZONA42021
ReserveNEW-MEXICO42023
MagdalenaNEW-MEXICO42024
RedingtonARIZONA32023
FlagstaffARIZONA22022
Peña BlancaARIZONA22005
WilliamsARIZONA22018
CutterARIZONA22014
AmadoARIZONA22022
McnealARIZONA22009
Sunizona 2ARIZONA22016
Vicks PeakNEW-MEXICO22016
PrescottARIZONA12021
PomereneARIZONA12024
MaineARIZONA12024

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