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

Black-billed Magpie Population Trend in New Mexico

All statesGeneralists

Black-billed Magpie in New Mexico has declined: down 41% on the route-weighted index since 1970.

-41%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 →
22Routes 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 →
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 Black-billed Magpie 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 Black-billed Magpie in New Mexico. See the full index history below.

Black-billed Magpie Population Forecast in New Mexico

If the recent trend holds, Black-billed Magpie in New Mexico is projected to rise about 17% by 2029 — from 1.1 in 2024 to a central estimate of 1.3 (95% range 0.00–3.5). A 5-year backtest shows a typical error of ±20.2%, with 100% of held-out values landing inside the 95% band.

+17%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 →
1.3Projected 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 →
0.00–3.595% 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 →
±20.2%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-billed Magpie in New Mexico is projected to rise about 17% by 2029 — from 1.1 in 2024 to a central estimate of 1.3 (95% range 0.00–3.5). A 5-year backtest shows a typical error of ±20.2%, 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 →
20251.40.003.6
20261.40.003.6
20271.40.003.5
20281.30.003.5
20291.30.003.5

Black-billed Magpie Survey Routes in New Mexico

Routes recording Black-billed Magpie 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 →
Aztec5419891988
Farmington4119871975
Stinking Lk.3519991992
Ojo Sarco2920241968
Angel Fire 21620242005
La Plata 21020162014
Pecos820171991
Cebolla620231977
Angel Fire620021992
Clovis520012000
Dulce420242000
Nageesi320082003
Farley320141979
Shiprock320031996
La Plata320131990
Capulin219941994
Sedan220012001
Gallinas220241992
Grenville120011968
Salt Lake 2120102003
La Cienega120191999
Maxwell120171996

Black-billed Magpie Population Trend in Other States

alaskaarizonacaliforniacoloradoidahokansasminnesotamontananebraskanevadanorth-dakotaoklahomaoregonsouth-dakotautahwashingtonwyoming

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