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

Black-headed Grosbeak Population Trend in Texas

All statesGeneralists

Black-headed Grosbeak in Texas has fallen sharply: down 69% on the route-weighted index since 1971.

-69%Since 1971TrendPercent 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 →
10Routes 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 →
51YearsYears 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 TexasNotable 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 declinecomputed 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 fallen sharply in Texas: down 69% on the route-weighted index since 1971.

Black-headed Grosbeak Population Forecast in Texas

If the recent trend holds, Black-headed Grosbeak in Texas is projected to stay roughly flat through 2029, near 0.05 (95% range 0.00–0.14). A 5-year backtest shows a typical error of ±141.7%, with 100% of held-out values landing inside the 95% band.

n/aChange 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 →
0.05Projected 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 →
0.00–0.1495% 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 →
±141.7%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, Black-headed Grosbeak in Texas is projected to stay roughly flat through 2029, near 0.05 (95% range 0.00–0.14). A 5-year backtest shows a typical error of ±141.7%, with 100% of held-out values landing inside the 95% band.19692029
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 →
20250.050.000.15
20260.050.000.14
20270.050.000.14
20280.050.000.14
20290.050.000.14

Black-headed Grosbeak Survey Routes in Texas

Routes recording Black-headed Grosbeak in Texas.
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 →
Valentine319871969
Bear Mtn320241988
Chisos Basin220231996
Salt Flat220062006
Kingsville119691969
Sierra Blanc120022002
Ft. Davis120232004
Toyahvale120241997
Hot Springs119971997
Longfellow120222010

Black-headed Grosbeak Population Trend in Other States

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