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Species · Nevada · BBS 2026 Release · 1966–2025

Black-billed Magpie Population Trend in Nevada

All statesGeneralists

Black-billed Magpie in Nevada has surged: up 160% on the route-weighted index since 1970.

+160%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 →
38Routes 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 NevadaNotable 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-billed Magpie has surged in Nevada: up 160% on the route-weighted index since 1970.

Black-billed Magpie Population Forecast in Nevada

If the recent trend holds, Black-billed Magpie in Nevada is projected to rise about 42% by 2030 — from 6.4 in 2025 to a central estimate of 9.1 (95% range 0.00–19). A 5-year backtest shows a typical error of ±97%, with 100% of held-out values landing inside the 95% band.

+42%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 →
9.1Projected 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 →
0.00–1995% 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 →
±97%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 Nevada is projected to rise about 42% by 2030 — from 6.4 in 2025 to a central estimate of 9.1 (95% range 0.00–19). A 5-year backtest shows a typical error of ±97%, 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 →
20268.80.0018
20278.80.0018
20288.90.0019
20299.00.0019
20309.10.0019

Black-billed Magpie Survey Routes in Nevada

Routes recording Black-billed Magpie in Nevada.
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 →
Toiyabe Nf6020241987
Gardnerville 25520252013
Fallon2820251992
Gardnerville2620121992
Chimney Res.2220252005
Ruby Valley1820011997
Fish Creek1520211997
Darroughs Hot Spgs1420242000
Majors Place1320251968
Oreana1220032002
Ruby Valley 21020242004
Calico Spr819741970
Jarbidge820152006
Humboldt Nf820191993
Carson River720052001
Sand Pass520251987
Rye Patch519871968
Eureka520221968
Charleston Reservoir520242024
Dinner Sta419931968
Nixon420251973
Cortez320251968
Mizpah320241990
Humboldt Nf 2320252021
Bald Mtn.320181996

Black-billed Magpie Population Trend in Other States

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