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

Brewer's Blackbird In Great Basin

All regionsGreat BasinGeneralists

Brewer's Blackbird in Great Basin has declined: down 28% on the route-weighted index since 1970.

-28%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 →
247Routes 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 →

No notable trend signals for Brewer's Blackbird in Great Basin. See the full index history below.

Brewer's Blackbird In Great Basin Population Forecast

If the recent trend holds, Brewer's Blackbird in Great Basin is projected to fall about 25% by 2029 — from 26 in 2024 to a central estimate of 19 (95% range 1.8–37). A 5-year backtest shows a typical error of ±21.6%, 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 →
19Projected 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 →
1.8–3795% 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 →
±21.6%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, Brewer's Blackbird in Great Basin is projected to fall about 25% by 2029 — from 26 in 2024 to a central estimate of 19 (95% range 1.8–37). A 5-year backtest shows a typical error of ±21.6%, 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 →
2025224.139
2026213.539
2027202.938
2028202.337
2029191.837

Routes In Great Basin

Routes recording Brewer's Blackbird 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 →
DorrisCALIFORNIA6462019
LikelyCALIFORNIA5072024
CedarvilleCALIFORNIA3282024
UmatillaOREGON3032023
Toiyabe NfNEVADA2632024
Modoc Point 2OREGON1772024
MacdoelCALIFORNIA1602019
JosephOREGON1522024
MesaWASHINGTON1512008
PrincetonOREGON1421985
Modoc PointOREGON1342018
Columbia NwrWASHINGTON1282022
Ruby Valley 2NEVADA1242024
Malheur NwrOREGON1212022
NubieberCALIFORNIA1152018
Crowley LakeCALIFORNIA972024
Fandango CanOREGON972024
HarwoodWASHINGTON951997
OthelloWASHINGTON911991
Glenns FerryIDAHO841986
RavendaleCALIFORNIA752024
Catlow RimOREGON752024
GardnervilleNEVADA732012
YakimaWASHINGTON732024
Walla WallaWASHINGTON711993

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