BirdAnalyst
Species · BCR 37 · BBS 2025 Release · 1966–2024

Boat-tailed Grackle In Gulf Coastal Prairie

All regionsGulf Coastal PrairieGeneralists

Boat-tailed Grackle in Gulf Coastal Prairie has edged up: up 22% on the route-weighted index since 1969.

+22%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 →
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 SignalsNotable 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 Boat-tailed Grackle in Gulf Coastal Prairie. See the full index history below.

Boat-tailed Grackle In Gulf Coastal Prairie Population Forecast

If the recent trend holds, Boat-tailed Grackle in Gulf Coastal Prairie is projected to fall about 22% by 2029 — from 27 in 2024 to a central estimate of 21 (95% range 0.00–55). A 5-year backtest shows a typical error of ±104%, with 100% of held-out values landing inside the 95% band.

-22%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 →
21Projected 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 →
0.00–5595% 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 →
±104%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 fall about 22% by 2029 — from 27 in 2024 to a central estimate of 21 (95% range 0.00–55). A 5-year backtest shows a typical error of ±104%, with 100% of held-out values landing inside the 95% band.19672029
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 →
2025220.0056
2026220.0056
2027210.0056
2028210.0055
2029210.0055

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 ChenierLOUISIANA3512024
Ltl Chenier 2LOUISIANA2242011
Gran ChenierLOUISIANA2151982
Forked Island 2LOUISIANA1912011
CreoleLOUISIANA1191987
Forked IslandLOUISIANA732024
IndianolaTEXAS582024
Sabine NwrLOUISIANA422008
Sabine Nwr 2LOUISIANA412017
LafitteLOUISIANA321991
KaplanLOUISIANA312023
Hackberry 2LOUISIANA282024
EstherLOUISIANA192024
Hinkles FerTEXAS172022
ChinquapinTEXAS112024
WinnieTEXAS102024
MauriceLOUISIANA82024
Ville PlatteLOUISIANA81993
HackberryLOUISIANA72004
WoodlawnLOUISIANA72021
Vinton 2LOUISIANA62023
Moon LakeTEXAS62011
JuniorLOUISIANA51991
Oyster LakeTEXAS52023
Bayside 3TEXAS42022

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