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

Brown-headed Cowbird Population Trend in New Mexico

All statesGeneralists

Brown-headed Cowbird in New Mexico has held roughly steady: down 9% on the route-weighted index since 1970.

-9%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 →
85Routes 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 Brown-headed Cowbird 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 Brown-headed Cowbird in New Mexico. See the full index history below.

Brown-headed Cowbird Population Forecast in New Mexico

If the recent trend holds, Brown-headed Cowbird in New Mexico is projected to rise about 66% by 2030 — from 1.9 in 2025 to a central estimate of 3.1 (95% range 0.39–5.9). A 5-year backtest shows a typical error of ±93.7%, with 100% of held-out values landing inside the 95% band.

+66%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 →
3.1Projected 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 →
0.39–5.995% 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 →
±93.7%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, Brown-headed Cowbird in New Mexico is projected to rise about 66% by 2030 — from 1.9 in 2025 to a central estimate of 3.1 (95% range 0.39–5.9). A 5-year backtest shows a typical error of ±93.7%, 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 →
20263.20.445.9
20273.20.435.9
20283.20.415.9
20293.10.405.9
20303.10.395.9

Brown-headed Cowbird Survey Routes in New Mexico

Routes recording Brown-headed Cowbird 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 →
Mesilla2020001992
Floyd1820191975
Aztec1819891988
San Antonio1719771974
Capulin1519931993
Pastura1420161994
Sunshine Wll1020211992
Red Rock920251992
Claunch 2920252001
Valencia819971968
Angel Fire820021992
Variadero820221994
Sabinoso820211980
Tucumcari719751975
Claunch720001978
Laborcita 2720252022
Nageesi620251970
Farmington519871975
Correo519821977
Laborcita520191992
Angel Fire 2520252005
Crownpoint419961988
Reserve420251993
Pinon420241992
Logan420251977

Brown-headed Cowbird Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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