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

Blue Grosbeak In Tamaulipan Brushlands

All regionsTamaulipan BrushlandsGeneralists

Blue Grosbeak 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 →
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 Blue Grosbeak in Tamaulipan Brushlands. See the full index history below.

Forecast

If the recent trend holds, Blue Grosbeak in Tamaulipan Brushlands is projected to fall about 30% by 2029 — from 2.9 in 2024 to a central estimate of 2.0 (95% range 0.00–4.9). A 5-year backtest shows a typical error of ±49.1%, with 100% of held-out values landing inside the 95% band.

-30%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 →
2.0Projected 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 →
0.00–4.995% 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 →
±49.1%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, Blue Grosbeak in Tamaulipan Brushlands is projected to fall about 30% by 2029 — from 2.9 in 2024 to a central estimate of 2.0 (95% range 0.00–4.9). A 5-year backtest shows a typical error of ±49.1%, 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 →
20252.10.004.9
20262.00.004.9
20272.00.004.9
20282.00.004.9
20292.00.004.9

Routes In Tamaulipan Brushlands

Routes recording Blue Grosbeak 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 →
RachalTEXAS192023
Agua NuevaTEXAS172023
KingsvilleTEXAS82024
MillettTEXAS82012
HondoTEXAS72024
RandadoTEXAS52024
CatarinaTEXAS42010
Encinal 2TEXAS42019
Cavasara Cr.TEXAS42013
EncinalTEXAS32010
San YgnacioTEXAS31985
GuerraTEXAS32023
Catarina 3TEXAS32024
LaredoTEXAS32023
Pedro CreekTEXAS32010
Mirando CityTEXAS22024
La PryorTEXAS22005
El IndioTEXAS22001
El SauzTEXAS22023
DilleyTEXAS22024
SejitaTEXAS22024
HeidelbergTEXAS22024
Millett 2TEXAS22024
ZapataTEXAS11979
George WestTEXAS12024

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