BirdAnalyst
Species · BBS 2025 Release · 1966–2024

Boat-tailed Grackle

IcteridaeWetland birdsQuiscalus major

Boat-tailed Grackle has fallen sharply: down 53% on the route-weighted index since 1968.

-53%Since 1968TrendPercent 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 →
236RoutesSurvey 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 Boat-tailed Grackle

The Boat-tailed Grackle (Quiscalus major) 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 236 Breeding Bird Survey routes across 13 states, most concentrated in the Southeastern Coastal Plain.
Family
Icteridae · Wetland birds

Notable Boat-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 →

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 →

Boat-tailed Grackle has fallen sharply in surveyed states: down 53% on the route-weighted index since 1968.

Boat-tailed Grackle Population Forecast

If the recent trend holds, Boat-tailed Grackle is projected to rise about 30% by 2029 — from 0.53 in 2024 to a central estimate of 0.69 (95% range 0.10–1.3). A 5-year backtest shows a typical error of ±65.3%, with 100% of held-out values landing inside the 95% band.

+30%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 →
0.69Projected 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 →
0.10–1.395% 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 →
±65.3%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, Boat-tailed Grackle is projected to rise about 30% by 2029 — from 0.53 in 2024 to a central estimate of 0.69 (95% range 0.10–1.3). A 5-year backtest shows a typical error of ±65.3%, with 100% of held-out values landing inside the 95% band.19662029
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 →
20250.710.121.3
20260.710.111.3
20270.700.111.3
20280.700.101.3
20290.690.101.3

Where the Boat-tailed Grackle Is Detected

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

Boat-tailed Grackle Population Trend by State

Boat-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 →
Alabama-54%196810
Delaware+14%19689
Florida-42%1968104
Georgia-93%196915
Louisiana+58%196940
Maryland-65%19694
Mississippi-10%20033
New Jersey+25%19814
New Yorkinsufficient datan/a1
North Carolina+21%196919
South Carolina-62%19686
Texas-50%197114
Virginia-64%19807

Boat-tailed Grackle Population Trend by Region

Bird Conservation Regions are the ecological unit for trends.

Boat-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 →
Mississippi Alluvial Valley-73%197613
Southeastern Coastal Plain-35%196885
New England / Mid-Atlantic Coast-5%196823
Peninsular Florida-49%196876
Gulf Coastal Prairie+22%196935

Boat-tailed Grackle Conservation Status

Our route-weighted index shows it down about 52% since 1968.

Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22. Trend is a route-weighted relative-abundance index, not an absolute population.