BirdAnalyst
Species · BCR 9 · BBS 2026 Release · 1966–2025

Black-headed Grosbeak In Great Basin

All regionsGreat BasinForest birds

Black-headed Grosbeak in Great Basin has surged: up 364% on the route-weighted index since 1970.

+364%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 →
175Routes 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 →
57YearsYears 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 364% 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 26% by 2030 — from 2.8 in 2025 to a central estimate of 3.5 (95% range 2.7–4.3). A 5-year backtest shows a typical error of ±23.7%, with 100% of held-out values landing inside the 95% band.

+26%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 →
3.5Projected 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 →
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 →
±23.7%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 Great Basin is projected to rise about 26% by 2030 — from 2.8 in 2025 to a central estimate of 3.5 (95% range 2.7–4.3). A 5-year backtest shows a typical error of ±23.7%, with 100% of held-out values landing inside the 95% band.19682030
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 →
20263.32.54.2
20273.42.54.2
20283.42.64.3
20293.52.64.3
20303.52.74.3

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 →
KendallWASHINGTON342025
SnowdenWASHINGTON282025
Blewett PassWASHINGTON282025
Lake ChelanWASHINGTON242025
Iron GateCALIFORNIA232019
Badger CreekOREGON202025
NewhalemWASHINGTON182025
EllensburgWASHINGTON182025
NighthawkWASHINGTON182025
TwispWASHINGTON162024
ArdenvoirWASHINGTON151987
ConcreteWASHINGTON142025
MazamaWASHINGTON122022
E. Mt. AdamsWASHINGTON122025
MacdoelCALIFORNIA112019
Ruby ValleyNEVADA112001
L. WenatcheeWASHINGTON112025
GiffordIDAHO92017
JoelIDAHO92024
Mt HoodOREGON92025
Modoc Point 2OREGON92025
NewcastleUTAH92025
SquirrelIDAHO82025
Wizard FallsOREGON82025
Hardware RanchUTAH82023

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.