BirdAnalyst
Species · BCR 37 · BBS 2026 Release · 1966–2025

Boat-tailed Grackle In Gulf Coastal Prairie

All regionsGulf Coastal PrairieWetland birds

Boat-tailed Grackle in Gulf Coastal Prairie has risen sharply: up 53% on the route-weighted index since 1969.

+53%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 →
35Routes 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 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 →

Boat-tailed Grackle has risen sharply in Gulf Coastal Prairie: up 53% on the route-weighted index since 1969.

Boat-tailed Grackle In Gulf Coastal Prairie Population Forecast

If the recent trend holds, Boat-tailed Grackle in Gulf Coastal Prairie is projected to rise about 17% by 2030 — from 17 in 2025 to a central estimate of 20 (95% range 0.00–54). A 5-year backtest shows a typical error of ±111.8%, with 100% of held-out values landing inside the 95% band.

+17%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 →
20Projected 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 →
0.00–5495% 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 →
±111.8%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 in Gulf Coastal Prairie is projected to rise about 17% by 2030 — from 17 in 2025 to a central estimate of 20 (95% range 0.00–54). A 5-year backtest shows a typical error of ±111.8%, 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 →
2026210.0055
2027210.0055
2028210.0055
2029210.0054
2030200.0054

Routes In Gulf Coastal Prairie

Routes recording Boat-tailed Grackle in Gulf Coastal Prairie.
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 →
Ltl ChenierLOUISIANA2272025
Ltl Chenier 2LOUISIANA2242011
Gran ChenierLOUISIANA2151982
Forked Island 2LOUISIANA1912011
CreoleLOUISIANA1191987
Forked IslandLOUISIANA822025
IndianolaTEXAS582024
Sabine NwrLOUISIANA422008
Sabine Nwr 2LOUISIANA412017
LafitteLOUISIANA321991
KaplanLOUISIANA312023
Hackberry 2LOUISIANA302025
WinnieTEXAS212025
Hinkles FerTEXAS172022
MauriceLOUISIANA82024
Ville PlatteLOUISIANA81993
HackberryLOUISIANA72004
WoodlawnLOUISIANA72021
Moon LakeTEXAS62011
JuniorLOUISIANA51991
EstherLOUISIANA42025
ChinquapinTEXAS42025
Port AcresTEXAS42025
GlencoeLOUISIANA32018
Grand IsleLOUISIANA32019

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