BirdAnalyst
Species · New Mexico · BBS 2026 Release · 1966–2025

Black-headed Grosbeak Population Trend in New Mexico

All statesForest birds

Black-headed Grosbeak in New Mexico has surged: up 101% on the route-weighted index since 1970.

+101%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 →
56Routes 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 →
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 Black-headed Grosbeak 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 →

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 →

Black-headed Grosbeak has surged in New Mexico: up 101% on the route-weighted index since 1970.

Black-headed Grosbeak Population Forecast in New Mexico

If the recent trend holds, Black-headed Grosbeak in New Mexico is projected to fall about 22% by 2030 — from 4.3 in 2025 to a central estimate of 3.4 (95% range 2.0–4.8). A 5-year backtest shows a typical error of ±20.8%, with 100% of held-out values landing inside the 95% band.

-22%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 →
3.4Projected 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 →
2.0–4.895% 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 →
±20.8%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, Black-headed Grosbeak in New Mexico is projected to fall about 22% by 2030 — from 4.3 in 2025 to a central estimate of 3.4 (95% range 2.0–4.8). A 5-year backtest shows a typical error of ±20.8%, 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 →
20263.31.94.7
20273.31.94.7
20283.31.94.7
20293.42.04.7
20303.42.04.8

Black-headed Grosbeak Survey Routes in New Mexico

Routes recording Black-headed Grosbeak 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 →
Cloudcroft4620251975
Gallinas3720251992
Angel Fire 22420252005
Ojo Sarco1720251968
Emory Pass1320251993
Claunch 21320252001
Mt. Taylor 21120242014
Reserve1120251993
Mcgaffey720231994
Red Rock720252002
La Cienega620211970
Stinking Lk.619991992
Mt. Taylor620121993
Farmington519831975
Claunch520001978
Capitan Mtn.520171993
Pinon520241992
Aztec519891988
Carrizozo420251968
Vallecitos420251994
Mesilla420001992
Sunshine Wll420251999
Cebolla320231973
Torreon319781978
Pecos320171973

Black-headed Grosbeak Population Trend in Other States

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