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

Northern Bobwhite In Tamaulipan Brushlands

All regionsTamaulipan BrushlandsGame birds

Northern Bobwhite in Tamaulipan Brushlands has fallen sharply: down 50% on the route-weighted index since 1969.

-50%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 →

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 →

Northern Bobwhite has fallen sharply in Tamaulipan Brushlands: down 50% on the route-weighted index since 1969.

Northern Bobwhite In Tamaulipan Brushlands Population Forecast

If the recent trend holds, Northern Bobwhite in Tamaulipan Brushlands is projected to fall about 95% by 2030 — from 38 in 2025 to a central estimate of 2.0 (95% range 0.00–57). A 5-year backtest shows a typical error of ±73.2%, with 100% of held-out values landing inside the 95% band.

-95%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 →
2.0Projected 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 →
0.00–5795% 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 →
±73.2%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, Northern Bobwhite in Tamaulipan Brushlands is projected to fall about 95% by 2030 — from 38 in 2025 to a central estimate of 2.0 (95% range 0.00–57). A 5-year backtest shows a typical error of ±73.2%, 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 →
20269.00.0064
20277.30.0063
20285.50.0061
20293.70.0059
20302.00.0057

Routes In Tamaulipan Brushlands

Routes recording Northern Bobwhite 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 →
RachalTEXAS892025
George WestTEXAS732025
RandadoTEXAS532025
San YgnacioTEXAS501985
CatarinaTEXAS492010
Agua NuevaTEXAS462023
Millett 2TEXAS412024
Cavasara Cr.TEXAS352025
MillettTEXAS342012
ZapataTEXAS331987
Mirando CityTEXAS332025
Catarina 2TEXAS322017
DilleyTEXAS322025
RaymondvilleTEXAS312025
SejitaTEXAS292024
GuerraTEXAS282025
HondoTEXAS252025
El SauzTEXAS222023
El IndioTEXAS192007
EncinalTEXAS152010
Catarina 3TEXAS152025
La PryorTEXAS122017
KingsvilleTEXAS72024
Pedro CreekTEXAS72010
LaredoTEXAS62021

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