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

Common Grackle In Tamaulipan Brushlands

All regionsTamaulipan BrushlandsGeneralists

Common Grackle in Tamaulipan Brushlands has collapsed: down 84% on the route-weighted index since 1977.

-84%Since 1977TrendPercent 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 →
12Routes 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 →
32YearsYears 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 →

Common Grackle has collapsed in Tamaulipan Brushlands: down 84% on the route-weighted index since 1977.

Common Grackle In Tamaulipan Brushlands Population Forecast

If the recent trend holds, Common Grackle in Tamaulipan Brushlands is projected to rise about 681% by 2029 — from 0.42 in 2024 to a central estimate of 3.3 (95% range 0.00–8.4). A 5-year backtest shows a typical error of ±1268.5%, with 100% of held-out values landing inside the 95% band.

+681%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 →
3.3Projected 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 →
0.00–8.495% 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 →
±1268.5%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, Common Grackle in Tamaulipan Brushlands is projected to rise about 681% by 2029 — from 0.42 in 2024 to a central estimate of 3.3 (95% range 0.00–8.4). A 5-year backtest shows a typical error of ±1268.5%, with 100% of held-out values landing inside the 95% band.19752029
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 →
20253.10.008.3
20263.10.008.3
20273.20.008.4
20283.20.008.4
20293.30.008.4

Routes In Tamaulipan Brushlands

Routes recording Common 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 →
El IndioTEXAS81998
Agua NuevaTEXAS62004
KingsvilleTEXAS42024
George WestTEXAS42022
ZapataTEXAS31976
EncinalTEXAS32008
La PryorTEXAS22004
LaredoTEXAS21999
Mirando CityTEXAS11979
HondoTEXAS12024
RaymondvilleTEXAS11990
MillettTEXAS11998

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