BirdAnalyst
Species · Arizona · BBS 2025 Release · 1966–2024

Great-tailed Grackle Population Trend in Arizona

All statesGeneralists

Great-tailed Grackle in Arizona has surged: up 518% on the route-weighted index since 1970.

+518%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 →
48Routes 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 →
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 Great-tailed Grackle Trends in ArizonaNotable 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 →

Great-tailed Grackle has surged in Arizona: up 518% on the route-weighted index since 1970.

Great-tailed Grackle Population Forecast in Arizona

If the recent trend holds, Great-tailed Grackle in Arizona is projected to rise about 166% by 2029 — from 4.7 in 2024 to a central estimate of 13 (95% range 7.9–17). A 5-year backtest shows a typical error of ±78.9%, with 20% of held-out values landing inside the 95% band.

+166%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 →
13Projected 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 →
7.9–1795% 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 →
±78.9%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 Arizona is projected to rise about 166% by 2029 — from 4.7 in 2024 to a central estimate of 13 (95% range 7.9–17). A 5-year backtest shows a typical error of ±78.9%, with 20% 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 →
2025127.116
2026127.317
2027127.517
2028127.717
2029137.917

Great-tailed Grackle Survey Routes in Arizona

Routes recording Great-tailed Grackle in Arizona.
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 →
Laguna9020231969
Cactus Forest7220241991
Araby7120231992
Casa Grande4320231989
Palo Verde 22620242014
Hope2620091990
Palo Verde1920131992
Hope 21920192014
Florence1719881968
Vicksburg1419891988
Riviera1220242004
Cibola Lake1220241994
Red Rock 21120242015
Seligman1120241991
Ajo 21120222009
Pomerene1020241977
Organ Pipe920231992
Alamo Res.520181993
Oatman420241988
Pinetop420032003
Amado420231993
Carr Mtn420211989
Skull Valley320241996
Cutter320141997
Red Rock320141992

Great-tailed Grackle Population Trend in Other States

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