BirdAnalyst
Species · California · BBS 2026 Release · 1966–2025

Great-tailed Grackle Population Trend in California

All statesWetland birds

Great-tailed Grackle in California has surged: up 53× on the route-weighted index since 1977.

53×Since 1977TrendPercent 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 →
67Routes In StateSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
50YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Great-tailed Grackle Trends in CaliforniaNotable 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 Great-tailed Grackle in California. See the full index history below.

Great-tailed Grackle Population Forecast in California

If the recent trend holds, Great-tailed Grackle in California is projected to rise about 79% by 2030 — from 1.8 in 2025 to a central estimate of 3.3 (95% range 0.04–6.6). A 5-year backtest shows a typical error of ±160.4%, with 100% of held-out values landing inside the 95% band.

+79%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 →
3.3Projected 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 →
0.04–6.695% 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 →
±160.4%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, Great-tailed Grackle in California is projected to rise about 79% by 2030 — from 1.8 in 2025 to a central estimate of 3.3 (95% range 0.04–6.6). A 5-year backtest shows a typical error of ±160.4%, with 100% of held-out values landing inside the 95% band.19732030
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 →
20263.10.006.4
20273.20.006.4
20283.20.006.5
20293.30.006.5
20303.30.046.6

Great-tailed Grackle Survey Routes in California

Routes recording Great-tailed Grackle in 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 →
Imperial Dam13720101973
Palo Verde10020251973
Alamo River9320181979
Brawley9120121983
Blythe5420032003
Parker Dam4520072003
Coachella Cn3620132000
Niland1720251979
Pennington1220252009
Buena Vista820192018
Orland720222011
Jofegan 2620252024
Moreno620252012
Ora Loma620242024
Pearblossom620252004
Orange Cove520122000
Athlone520072003
Creston420212021
Calif City420151995
Lockwood420252025
Glamis420182018
Harbor Lake 2420242016
Silver City420132013
Elizabeth Lk320162012
Atwater320072007

Great-tailed Grackle Population Trend in Other States

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