BirdAnalyst
Species · BBS 2026 Release · 1966–2025

Great-tailed Grackle Population Analysis

IcteridaeWetland birdsQuiscalus mexicanus

Great-tailed Grackle has edged down: down 18% on the route-weighted index since 1969.

-18%Since 1969TrendPercent 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 →
634RoutesSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
58Years SurveyedYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

About the Great-tailed Grackle

The Great-tailed Grackle (Quiscalus mexicanus) is a North American member of the Blackbirds & Orioles (Icteridae). In this analysis it is grouped with the wetland birds.

Size
6.5–17 in long (16–43 cm) — a small to medium songbird (typical for the family)
Habitat
Marshes, ponds, lakeshores and other freshwater wetlands.
Diet
Aquatic invertebrates, small fish, frogs and plant matter.
Range
Recorded on 634 Breeding Bird Survey routes across 19 states, most concentrated in the Shortgrass Prairie.
Family
Icteridae · Wetland birds

Notable Great-tailed Grackle TrendsNotable 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. See the full index history below.

Great-tailed Grackle Population Forecast

If the recent trend holds, Great-tailed Grackle is projected to stay roughly flat through 2030, near 1.4 (95% range 0.19–2.6). A 5-year backtest shows a typical error of ±13.1%, with 100% of held-out values landing inside the 95% band.

-1%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 →
1.4Projected 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 →
0.19–2.695% 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 →
±13.1%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 is projected to stay roughly flat through 2030, near 1.4 (95% range 0.19–2.6). A 5-year backtest shows a typical error of ±13.1%, with 100% of held-out values landing inside the 95% band.19672030
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 →
20261.50.252.7
20271.50.232.7
20281.40.222.7
20291.40.202.7
20301.40.192.6

Where the Great-tailed Grackle Is Detected

BBS routes recording Great-tailed Grackle, sized by most recent count.

Great-tailed Grackle Population Trend by State

Great-tailed Grackle population trend by state.
TrendPercent 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 →Baseline yearThe first year of the smoothed window the trend is measured from. An earlier baseline means a longer record stands behind the number.Full methodology →Survey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
Arizona+390%197049
Arkansas-42%19855
California53×197767
Colorado+239%198443
Idahoinsufficient datan/a1
Illinoisinsufficient datan/a1
Iowa-24%19996
Kansas23×197351
Louisiana-80%197823
Missouri-65%199324
Nebraska+162%200118
Nevada+104%199415
New Mexico+655%197144
Oklahoma19×196956
Oregoninsufficient datan/a1
South Dakotainsufficient datan/a3
Texas-47%1969213
Utah-30%199612
Wyominginsufficient datan/a2

Great-tailed Grackle Population Trend by Region

Bird Conservation Regions are the ecological unit for trends.

Great-tailed Grackle population trend by Bird Conservation Region.
TrendPercent 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 →Baseline yearThe first year of the smoothed window the trend is measured from. An earlier baseline means a longer record stands behind the number.Full methodology →Survey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
Great Basin+550%199623
Southern Rockies / Colorado Plateau-58%197332
Shortgrass Prairie227×197499
Central Mixed Grass Prairie+129%197079
Edwards Plateau+521%197317
Oaks and Prairies-13%196972
Eastern Tallgrass Prairie-48%198046
Central Hardwoods-28%199316
West Gulf Coastal Plain / Ouachitas+114%197223
Coastal California14×200137
Sonoran and Mojave Deserts+813%197052
Sierra Madre Occidental-84%197318
Chihuahuan Desert15×197037
Tamaulipan Brushlands-54%196928
Gulf Coastal Prairie-51%196944

Great-tailed Grackle Conservation Status

Our route-weighted index shows it down about 18% since 1969.

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14. Trend is a route-weighted relative-abundance index, not an absolute population.