BirdAnalyst
Species · Nevada · BBS 2025 Release · 1966–2024

Black-headed Grosbeak Population Trend in Nevada

All statesGeneralists

Black-headed Grosbeak in Nevada has surged: up 95% on the route-weighted index since 1991.

+95%Since 1991TrendPercent 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 →
34YearsYears 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 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-headed Grosbeak has surged in Nevada: up 95% on the route-weighted index since 1991.

Black-headed Grosbeak Population Forecast in Nevada

If the recent trend holds, Black-headed Grosbeak in Nevada is projected to rise about 180% by 2029 — from 0.18 in 2024 to a central estimate of 0.50 (95% range 0.00–1.1). A 5-year backtest shows a typical error of ±83.1%, with 100% of held-out values landing inside the 95% band.

+180%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 →
0.50Projected 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 →
0.00–1.195% 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 →
±83.1%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 Nevada is projected to rise about 180% by 2029 — from 0.18 in 2024 to a central estimate of 0.50 (95% range 0.00–1.1). A 5-year backtest shows a typical error of ±83.1%, with 100% of held-out values landing inside the 95% band.19742029
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 →
20250.500.001.1
20260.500.001.1
20270.500.001.1
20280.500.001.1
20290.500.001.1

Black-headed Grosbeak Survey Routes in Nevada

Routes recording Black-headed Grosbeak 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 →
Ruby Valley1120011999
Humboldt Nf320191994
Jarbidge320151997
Hawthorne320011999
Ranchogrande220232001
Walker Can220241993
Ruby Valley 2220192009
Gardnerville220001995
Midas120011974
Dinner Sta119911991
Sand Pass120131998
Comins Lake120122005
Fish Creek120151998
Mizpah120192019
Austin120182008
Meadow Vally120231997
Humboldt Nf 2120242021
Majors Place120112011
Willis120241988
Chimney Res.120232005
Fallon120032000
Gardnerville 2120242018

Black-headed Grosbeak Population Trend in Other States

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