BirdAnalyst
Species · BCR 9 · BBS 2025 Release · 1966–2024

Black-headed Grosbeak In Great Basin

All regionsGreat BasinGeneralists

Black-headed Grosbeak in Great Basin has surged: up 358% on the route-weighted index since 1970.

+358%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 →
174Routes 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 →
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 SignalsNotable 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 Great Basin: up 358% on the route-weighted index since 1970.

Black-headed Grosbeak In Great Basin Population Forecast

If the recent trend holds, Black-headed Grosbeak in Great Basin is projected to rise about 25% by 2029 — from 2.8 in 2024 to a central estimate of 3.5 (95% range 2.7–4.3). A 5-year backtest shows a typical error of ±21.4%, with 100% of held-out values landing inside the 95% band.

+25%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 →
3.5Projected 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 →
2.7–4.395% 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 →
±21.4%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 Great Basin is projected to rise about 25% by 2029 — from 2.8 in 2024 to a central estimate of 3.5 (95% range 2.7–4.3). A 5-year backtest shows a typical error of ±21.4%, with 100% of held-out values landing inside the 95% band.19682029
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 →
20253.32.54.2
20263.42.54.2
20273.42.64.3
20283.52.64.3
20293.52.74.3

Routes In Great Basin

Routes recording Black-headed Grosbeak in Great Basin.
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 →
KendallWASHINGTON392024
ConcreteWASHINGTON272024
SnowdenWASHINGTON242024
Iron GateCALIFORNIA232019
Lake ChelanWASHINGTON232024
Mt HoodOREGON212024
NewhalemWASHINGTON202024
EllensburgWASHINGTON182024
Blewett PassWASHINGTON172024
TwispWASHINGTON162024
ArdenvoirWASHINGTON151987
Wizard FallsOREGON132024
RonaldWASHINGTON132024
White ChuckWASHINGTON132024
NighthawkWASHINGTON122024
MazamaWASHINGTON122022
MacdoelCALIFORNIA112019
Ruby ValleyNEVADA112001
Badger CreekOREGON112024
GiffordIDAHO92017
JoelIDAHO92024
LakeviewOREGON92024
L. WenatcheeWASHINGTON92024
E. Mt. AdamsWASHINGTON92024
Hardware RanchUTAH82023

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