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

Great-tailed Grackle In Gulf Coastal Prairie

All regionsGulf Coastal PrairieGeneralists

Great-tailed Grackle in Gulf Coastal Prairie has declined: down 49% on the route-weighted index since 1969.

-49%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 →
43Routes 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 →

No notable trend signals for Great-tailed Grackle in Gulf Coastal Prairie. See the full index history below.

Forecast

If the recent trend holds, Great-tailed Grackle in Gulf Coastal Prairie is projected to fall about 63% by 2029 — from 44 in 2024 to a central estimate of 16 (95% range 0.00–114). A 5-year backtest shows a typical error of ±43.4%, with 100% of held-out values landing inside the 95% band.

-63%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 →
16Projected 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 →
0.00–11495% 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 →
±43.4%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 Gulf Coastal Prairie is projected to fall about 63% by 2029 — from 44 in 2024 to a central estimate of 16 (95% range 0.00–114). A 5-year backtest shows a typical error of ±43.4%, 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 →
2025240.00121
2026220.00119
2027200.00117
2028180.00116
2029160.00114

Routes In Gulf Coastal Prairie

Routes recording Great-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 →
Lag AtascosaTEXAS2892024
Gran ChenierLOUISIANA1481976
Loyola Beach 2TEXAS1452024
L. Atascosa NwrTEXAS1322023
BaysideTEXAS1272010
Bayside 3TEXAS1212024
Bayside 2TEXAS1192004
PetronilaTEXAS1182024
CreoleLOUISIANA941987
StowellTEXAS932023
Forked Island 2LOUISIANA812011
IndianolaTEXAS612024
Ltl Chenier 2LOUISIANA602011
Oyster LakeTEXAS532024
Loyola BeachTEXAS422009
Moon Lake 2TEXAS292024
GlencoeLOUISIANA232012
WinnieTEXAS232024
ChinquapinTEXAS202024
DanburyTEXAS172024
Hinkles FerTEXAS142024
Goliad PrairieTEXAS132016
Port AcresTEXAS102024
MamouLOUISIANA81982
McfaddinTEXAS82016

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