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

Brewer's Blackbird In Great Basin

All regionsGreat BasinGeneralists

Brewer's Blackbird in Great Basin has edged down: down 20% on the route-weighted index since 1970.

-20%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 →
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 →

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 21% by 2030 — from 24 in 2025 to a central estimate of 19 (95% range 1.5–36). A 5-year backtest shows a typical error of ±20.6%, with 100% of held-out values landing inside the 95% band.

-21%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 →
19Projected 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 →
1.5–3695% 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 →
±20.6%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 21% by 2030 — from 24 in 2025 to a central estimate of 19 (95% range 1.5–36). A 5-year backtest shows a typical error of ±20.6%, 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 →
2026213.839
2027213.238
2028202.637
2029192.037
2030191.536

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
LikelyCALIFORNIA4302025
Toiyabe NfNEVADA2632024
Scootney ReservoirWASHINGTON2392025
JosephOREGON2292025
Modoc Point 2OREGON1702025
MacdoelCALIFORNIA1602019
MesaWASHINGTON1512008
RavendaleCALIFORNIA1442025
PrincetonOREGON1421985
Modoc PointOREGON1342018
Columbia NwrWASHINGTON1282022
Ruby Valley 2NEVADA1242024
Malheur NwrOREGON1212022
IngallsCALIFORNIA1162025
NubieberCALIFORNIA1152018
Ewan 2WASHINGTON1132025
UmatillaOREGON1092025
HarwoodWASHINGTON951997
OthelloWASHINGTON911991
Glenns FerryIDAHO841986
Catlow RimOREGON812025
Crowley LakeCALIFORNIA762025
GardnervilleNEVADA732012
AsotinWASHINGTON712025

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