BirdAnalyst
Species · BCR 32 · BBS 2026 Release · 1966–2025

Tricolored Blackbird In Coastal California

All regionsCoastal CaliforniaWetland birds

Tricolored Blackbird in Coastal California has fallen sharply: down 56% on the route-weighted index since 1970.

-56%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 →
70Routes 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 declinecomputed 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 →

Tricolored Blackbird has fallen sharply in Coastal California: down 56% on the route-weighted index since 1970.

Tricolored Blackbird In Coastal California Population Forecast

If the recent trend holds, Tricolored Blackbird in Coastal California is projected to rise about 18× by 2030 — from 0.84 in 2025 to a central estimate of 15 (95% range 0.00–73). A 5-year backtest shows a typical error of ±877.2%, with 100% of held-out values landing inside the 95% band.

18×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 →
15Projected 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 →
0.00–7395% 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 →
±877.2%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, Tricolored Blackbird in Coastal California is projected to rise about 18× by 2030 — from 0.84 in 2025 to a central estimate of 15 (95% range 0.00–73). A 5-year backtest shows a typical error of ±877.2%, 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 →
2026170.0074
2027170.0074
2028160.0074
2029160.0073
2030150.0073

Routes In Coastal California

Routes recording Tricolored Blackbird in Coastal California.
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 →
OnealsCALIFORNIA52902011
RiovistaCALIFORNIA3262024
AtwaterCALIFORNIA2332012
JacumbaCALIFORNIA2001999
Mark WestCALIFORNIA1401992
GreenfieldCALIFORNIA1132024
MorenoCALIFORNIA862017
PolomaCALIFORNIA861995
OrovilleCALIFORNIA802012
CopperopolisCALIFORNIA702022
Gold HillCALIFORNIA651990
BakersfieldCALIFORNIA602019
OilfieldsCALIFORNIA561976
VentucopaCALIFORNIA452002
LockwoodCALIFORNIA452022
Yolla BollyCALIFORNIA432022
AthloneCALIFORNIA412007
South LakeCALIFORNIA402006
ReddingCALIFORNIA381975
ShafterCALIFORNIA371989
CoyoteCALIFORNIA322014
ArvinCALIFORNIA312022
GlennCALIFORNIA312025
RumseyCALIFORNIA302006
HughsonCALIFORNIA302024

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