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

Bronzed Cowbird In Tamaulipan Brushlands

All regionsTamaulipan BrushlandsGeneralists

Bronzed Cowbird in Tamaulipan Brushlands has edged down: down 21% on the route-weighted index since 1969.

-21%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 →

No notable trend signals for Bronzed Cowbird in Tamaulipan Brushlands. See the full index history below.

Bronzed Cowbird In Tamaulipan Brushlands Population Forecast

If the recent trend holds, Bronzed Cowbird in Tamaulipan Brushlands is projected to rise about 19% by 2030 — from 7.1 in 2025 to a central estimate of 8.4 (95% range 0.00–21). A 5-year backtest shows a typical error of ±52.6%, with 100% of held-out values landing inside the 95% band.

+19%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 →
8.4Projected 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 →
0.00–2195% 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 →
±52.6%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, Bronzed Cowbird in Tamaulipan Brushlands is projected to rise about 19% by 2030 — from 7.1 in 2025 to a central estimate of 8.4 (95% range 0.00–21). A 5-year backtest shows a typical error of ±52.6%, 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 →
20269.00.0022
20278.90.0022
20288.70.0022
20298.60.0021
20308.40.0021

Routes In Tamaulipan Brushlands

Routes recording Bronzed Cowbird 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 →
ProgresoTEXAS792011
RaymondvilleTEXAS452025
MillettTEXAS302012
KingsvilleTEXAS152024
RachalTEXAS142023
SejitaTEXAS132024
ZapataTEXAS121987
Agua NuevaTEXAS112023
San YgnacioTEXAS91985
HeidelbergTEXAS82024
Mirando CityTEXAS72025
EncinalTEXAS72010
George WestTEXAS72025
DilleyTEXAS72025
GuerraTEXAS72018
RandadoTEXAS52025
HondoTEXAS52025
LaredoTEXAS52018
Millett 2TEXAS52024
Encinal 2TEXAS32023
La PryorTEXAS22017
El SauzTEXAS22023
Catarina 2TEXAS22017
Catarina 3TEXAS22025
Cavasara Cr.TEXAS22007

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