BirdAnalyst
Species · New Mexico · BBS 2025 Release · 1966–2024

Brewer's Sparrow Population Trend in New Mexico

All statesGeneralists

Brewer's Sparrow in New Mexico has held roughly steady: down 3% on the route-weighted index since 1977.

-3%Since 1977TrendPercent 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 →
20Routes In StateSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
45YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Brewer's Sparrow Trends in New MexicoNotable 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 Brewer's Sparrow in New Mexico. See the full index history below.

Brewer's Sparrow Population Forecast in New Mexico

If the recent trend holds, Brewer's Sparrow in New Mexico is projected to rise about 30% by 2029 — from 0.39 in 2024 to a central estimate of 0.51 (95% range 0.00–1.5). A 5-year backtest shows a typical error of ±118.9%, with 100% of held-out values landing inside the 95% band.

+30%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 →
0.51Projected 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 →
0.00–1.595% 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 →
±118.9%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, Brewer's Sparrow in New Mexico is projected to rise about 30% by 2029 — from 0.39 in 2024 to a central estimate of 0.51 (95% range 0.00–1.5). A 5-year backtest shows a typical error of ±118.9%, with 100% of held-out values landing inside the 95% band.19692029
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 →
20250.540.001.6
20260.530.001.6
20270.520.001.6
20280.510.001.6
20290.510.001.5

Brewer's Sparrow Survey Routes in New Mexico

Routes recording Brewer's Sparrow in New Mexico.
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 →
Stinking Lk.1219991992
Datil1019951994
Dulce720242000
La Plata620131990
Mt. Taylor 2520242022
Mt. Taylor520112010
Cebolla419771977
Horse Spgs420052005
Salt Lake 2320242015
Nageesi220241969
Grenville220101984
Fence Lake220151977
Maxwell220152009
La Plata 2220162014
Farmington119871975
Torreon120241975
Valencia119961980
Counselor120221992
Mcgaffey120082002
Quemado119971997

Brewer's Sparrow Population Trend in Other States

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