BirdAnalyst
Species · BCR 11 · BBS 2025 Release · 1966–2024

Black-headed Grosbeak In Prairie Potholes

All regionsPrairie PotholesGeneralists

Black-headed Grosbeak in Prairie Potholes has increased: up 30% on the route-weighted index since 1980.

+30%Since 1980TrendPercent 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 →
14Routes In RegionSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
43YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable SignalsNotable 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-headed Grosbeak in Prairie Potholes. See the full index history below.

Black-headed Grosbeak In Prairie Potholes Population Forecast

If the recent trend holds, Black-headed Grosbeak in Prairie Potholes is projected to stay roughly flat through 2029, near 0.04 (95% range 0.00–0.08). A 5-year backtest shows a typical error of ±18%, 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 →
0.04Projected 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 →
0.00–0.0895% 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 →
±18%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 Prairie Potholes is projected to stay roughly flat through 2029, near 0.04 (95% range 0.00–0.08). A 5-year backtest shows a typical error of ±18%, with 100% of held-out values landing inside the 95% band.19672029
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 →
20250.040.000.08
20260.040.000.08
20270.040.000.08
20280.040.000.08
20290.040.000.08

Routes In Prairie Potholes

Routes recording Black-headed Grosbeak in Prairie Potholes.
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 →
Douglas CrkNORTH-DAKOTA32024
GlasgowMONTANA22009
Hay LakeMONTANA11988
ClevelandMONTANA12010
SacoMONTANA12021
LambertMONTANA12021
ReganNORTH-DAKOTA12018
CarpioNORTH-DAKOTA11993
StanleyNORTH-DAKOTA12023
Powers LakeNORTH-DAKOTA11980
ParshallNORTH-DAKOTA12006
BraddockNORTH-DAKOTA12014
GeddesSOUTH-DAKOTA11967
GormanSOUTH-DAKOTA12000

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