BirdAnalyst
Species · BCR 36 · BBS 2025 Release · 1966–2024

Great-tailed Grackle In Tamaulipan Brushlands

All regionsTamaulipan BrushlandsGeneralists

Great-tailed Grackle in Tamaulipan Brushlands has declined: down 47% on the route-weighted index since 1969.

-47%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 →
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 Tamaulipan Brushlands. See the full index history below.

Great-tailed Grackle In Tamaulipan Brushlands Population Forecast

If the recent trend holds, Great-tailed Grackle in Tamaulipan Brushlands is projected to rise about 31% by 2029 — from 45 in 2024 to a central estimate of 59 (95% range 0.00–229). A 5-year backtest shows a typical error of ±135.4%, with 100% of held-out values landing inside the 95% band.

+31%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 →
59Projected 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 →
0.00–22995% 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 →
±135.4%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 31% by 2029 — from 45 in 2024 to a central estimate of 59 (95% range 0.00–229). A 5-year backtest shows a typical error of ±135.4%, 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 →
2025660.00237
2026650.00235
2027630.00233
2028610.00231
2029590.00229

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
RaymondvilleTEXAS1442024
EncinalTEXAS1252010
HeidelbergTEXAS952024
KingsvilleTEXAS922024
George WestTEXAS772024
La PryorTEXAS552017
Encinal 2TEXAS522024
San YgnacioTEXAS481985
ZapataTEXAS371987
RachalTEXAS352023
Catarina 2TEXAS262017
Mirando CityTEXAS212024
DilleyTEXAS192024
HondoTEXAS182024
RandadoTEXAS162024
CatarinaTEXAS92010
Pedro CreekTEXAS82010
El IndioTEXAS72007
MillettTEXAS72012
El SauzTEXAS62023
SejitaTEXAS62023
Cavasara Cr.TEXAS62023
Agua NuevaTEXAS52023
Catarina 3TEXAS42024

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