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

Grassland Birds In New Mexico

All statesNew Mexico

11 species in this guild. As a group they are -48%Guild trendA mean-index aggregate across the species in this group — the structural direction of the guild, with individual-species noise smoothed out.Full methodology → since 1970.

Guild SignalsNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

guild collapsecomputed 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 →

Grassland birds as a group have declined in New Mexico, down 48% since 1970.

Grassland Birds In New Mexico Population Forecast

If the recent trend holds, Grassland birds in New Mexico is projected to fall about 41% by 2029 — from 8.2 in 2024 to a central estimate of 4.8 (95% range 0.00–11). A 5-year backtest shows a typical error of ±17.7%, with 100% of held-out values landing inside the 95% band.

-41%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 →
4.8Projected 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 →
0.00–1195% 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 →
±17.7%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, Grassland birds in New Mexico is projected to fall about 41% by 2029 — from 8.2 in 2024 to a central estimate of 4.8 (95% range 0.00–11). A 5-year backtest shows a typical error of ±17.7%, 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 →
20255.70.0012
20265.40.0012
20275.20.0011
20285.00.0011
20294.80.0011

Member Species In New Mexico

Grassland birds species in New Mexico.
TrendPercent 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 →
DickcisselCardinalidae-76%
Lark BuntingPasserellidae-67%
Savannah SparrowPasserellidae-66%
Horned LarkAlaudidae-63%
Ring-necked PheasantPhasianidae-63%
Western MeadowlarkIcteridae-49%
Cassin's SparrowPasserellidae+2%
Northern BobwhiteOdontophoridae+79%
Grasshopper SparrowPasserellidae+135%
Lark SparrowPasserellidae+195%
Vesper SparrowPasserellidae+437%

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