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

Indigo Bunting In Tamaulipan Brushlands

All regionsTamaulipan BrushlandsGeneralists

Indigo Bunting in Tamaulipan Brushlands has fallen sharply: down 64% on the route-weighted index since 1971.

-64%Since 1971TrendPercent 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 →
15Routes 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 →
23YearsYears 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 →

Indigo Bunting has fallen sharply in Tamaulipan Brushlands: down 64% on the route-weighted index since 1971.

Indigo Bunting In Tamaulipan Brushlands Population Forecast

If the recent trend holds, Indigo Bunting in Tamaulipan Brushlands is projected to fall about 22% by 2029 — from 0.17 in 2024 to a central estimate of 0.13 (95% range 0.00–0.43). A 5-year backtest shows a typical error of ±40.2%, 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 →
0.13Projected 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 →
0.00–0.4395% 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 →
±40.2%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, Indigo Bunting in Tamaulipan Brushlands is projected to fall about 22% by 2029 — from 0.17 in 2024 to a central estimate of 0.13 (95% range 0.00–0.43). A 5-year backtest shows a typical error of ±40.2%, 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 →
20250.140.000.44
20260.140.000.44
20270.130.000.44
20280.130.000.43
20290.130.000.43

Routes In Tamaulipan Brushlands

Routes recording Indigo Bunting 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 →
MillettTEXAS62012
EncinalTEXAS32000
Catarina 3TEXAS22024
LaredoTEXAS22013
Cavasara Cr.TEXAS21998
KingsvilleTEXAS11984
Mirando CityTEXAS11981
George WestTEXAS11974
La PryorTEXAS12003
HondoTEXAS12022
El IndioTEXAS11971
RaymondvilleTEXAS11998
DilleyTEXAS12023
GuerraTEXAS11998
ProgresoTEXAS12005

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