BirdAnalyst
Species · BBS 2026 Release · 1966–2025

Black-headed Grosbeak Population Analysis

CardinalidaeForest birdsPheucticus melanocephalus

Black-headed Grosbeak has surged: up 426% on the route-weighted index since 1969.

+426%Since 1969TrendPercent 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 →
1,078RoutesSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
58Years SurveyedYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

About the Black-headed Grosbeak

The Black-headed Grosbeak (Pheucticus melanocephalus) is a North American member of the Cardinals & Grosbeaks (Cardinalidae). In this analysis it is grouped with the forest birds.

Size
4.5–8.5 in long (12–22 cm) — a medium songbird (typical for the family)
Habitat
Woodlands and forest edges, including wooded suburbs and parks.
Diet
Insects and spiders gleaned from foliage and bark, with seeds and berries in season.
Range
Recorded on 1,078 Breeding Bird Survey routes across 18 states, most concentrated in the Southern Rockies / Colorado Plateau.
Family
Cardinalidae · Forest birds

Notable Black-headed Grosbeak TrendsNotable 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 surveyed states: up 425% on the route-weighted index since 1969.

Black-headed Grosbeak Population Forecast

If the recent trend holds, Black-headed Grosbeak is projected to stay roughly flat through 2030, near 1.3 (95% range 0.93–1.8). A 5-year backtest shows a typical error of ±19.9%, with 100% of held-out values landing inside the 95% band.

+3%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 →
1.3Projected 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 →
0.93–1.895% 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 →
±19.9%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 is projected to stay roughly flat through 2030, near 1.3 (95% range 0.93–1.8). A 5-year backtest shows a typical error of ±19.9%, with 100% of held-out values landing inside the 95% band.19672030
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 →
20261.30.901.7
20271.30.911.7
20281.30.911.7
20291.30.921.7
20301.30.931.8

Where the Black-headed Grosbeak Is Detected

BBS routes recording Black-headed Grosbeak, sized by most recent count.

Black-headed Grosbeak Population Trend by State

Black-headed Grosbeak population trend by state.
TrendPercent 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 →Baseline yearThe first year of the smoothed window the trend is measured from. An earlier baseline means a longer record stands behind the number.Full methodology →Survey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
Alaskainsufficient datan/a1
Arizona+123%197045
California-8%1970232
Colorado+263%1970114
Idaho+354%197153
Kansas-37%197214
Montana+376%197277
Nebraska+233%197022
Nevada+106%199122
New Mexico+101%197056
North Dakota+345%197222
Oklahomainsufficient datan/a1
Oregon+13%1970118
South Dakota+871%196942
Texas-53%197110
Utah+222%197078
Washington+316%1970102
Wyoming+158%197069

Black-headed Grosbeak Population Trend by Region

Bird Conservation Regions are the ecological unit for trends.

Black-headed Grosbeak population trend by Bird Conservation Region.
TrendPercent 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 →Baseline yearThe first year of the smoothed window the trend is measured from. An earlier baseline means a longer record stands behind the number.Full methodology →Survey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
Northern Pacific Rainforest+10%1970130
Great Basin+364%1970175
Northern Rockies+356%1970166
Prairie Potholes+42%198015
Sierra Nevada+6%197039
Southern Rockies / Colorado Plateau+121%1970196
Badlands and Prairies+865%196997
Shortgrass Prairie+233%197039
Central Mixed Grass Prairie+76%196928
Coastal California-13%1970114
Sonoran and Mojave Deserts-5%197118
Sierra Madre Occidental+76%197034
Chihuahuan Desert+114%197026

Black-headed Grosbeak Conservation Status

Our route-weighted index shows it up about 426% since 1969.

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14. Trend is a route-weighted relative-abundance index, not an absolute population.