BirdAnalyst
Species · BCR 36 · BBS 2026 Release · 1966–2025

Great-tailed Grackle In Tamaulipan Brushlands

All regionsTamaulipan BrushlandsWetland birds

Great-tailed Grackle in Tamaulipan Brushlands has fallen sharply: down 54% on the route-weighted index since 1969.

-54%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 →
28Routes 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 →
58YearsYears 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 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 →

Great-tailed Grackle has fallen sharply in Tamaulipan Brushlands: down 54% on the route-weighted index since 1969.

Great-tailed Grackle In Tamaulipan Brushlands Population Forecast

If the recent trend holds, Great-tailed Grackle in Tamaulipan Brushlands is projected to rise about 93% by 2030 — from 28 in 2025 to a central estimate of 54 (95% range 0.00–223). A 5-year backtest shows a typical error of ±130.4%, with 100% of held-out values landing inside the 95% band.

+93%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 →
54Projected 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 →
0.00–22395% 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 →
±130.4%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 Tamaulipan Brushlands is projected to rise about 93% by 2030 — from 28 in 2025 to a central estimate of 54 (95% range 0.00–223). A 5-year backtest shows a typical error of ±130.4%, 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 →
2026620.00231
2027600.00229
2028580.00227
2029560.00225
2030540.00223

Routes In Tamaulipan Brushlands

Routes recording Great-tailed Grackle in Tamaulipan Brushlands.
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 →
ProgresoTEXAS5482011
RaymondvilleTEXAS1552025
EncinalTEXAS1252010
HeidelbergTEXAS952024
KingsvilleTEXAS922024
La PryorTEXAS552017
San YgnacioTEXAS481985
ZapataTEXAS371987
Encinal 2TEXAS372025
George WestTEXAS302025
Catarina 2TEXAS262017
HondoTEXAS232025
RandadoTEXAS192025
RachalTEXAS182025
GuerraTEXAS132025
CatarinaTEXAS92010
DilleyTEXAS82025
Pedro CreekTEXAS82010
El IndioTEXAS72007
MillettTEXAS72012
El SauzTEXAS62023
SejitaTEXAS62023
Agua NuevaTEXAS52023
Millett 2TEXAS42024
Mirando CityTEXAS32025

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