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

Swainson's Hawk In Tamaulipan Brushlands

All regionsTamaulipan BrushlandsBirds of prey

Swainson's Hawk in Tamaulipan Brushlands has fallen sharply: down 61% on the route-weighted index since 1969.

-61%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 →
27Routes 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 →

Swainson's Hawk has fallen sharply in Tamaulipan Brushlands: down 61% on the route-weighted index since 1969.

Swainson's Hawk In Tamaulipan Brushlands Population Forecast

If the recent trend holds, Swainson's Hawk in Tamaulipan Brushlands is projected to rise about 149% by 2030 — from 0.18 in 2025 to a central estimate of 0.45 (95% range 0.00–2.1). A 5-year backtest shows a typical error of ±75.4%, with 100% of held-out values landing inside the 95% band.

+149%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 →
0.45Projected 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 →
0.00–2.195% 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 →
±75.4%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, Swainson's Hawk in Tamaulipan Brushlands is projected to rise about 149% by 2030 — from 0.18 in 2025 to a central estimate of 0.45 (95% range 0.00–2.1). A 5-year backtest shows a typical error of ±75.4%, 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 →
20260.560.002.2
20270.540.002.1
20280.510.002.1
20290.480.002.1
20300.450.002.1

Routes In Tamaulipan Brushlands

Routes recording Swainson's Hawk 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 SauzTEXAS42023
San YgnacioTEXAS31985
CatarinaTEXAS32010
ProgresoTEXAS32009
Pedro CreekTEXAS32005
Millett 2TEXAS32022
La PryorTEXAS22017
RaymondvilleTEXAS22024
Catarina 3TEXAS22024
LaredoTEXAS22021
RachalTEXAS12023
Agua NuevaTEXAS12023
ZapataTEXAS11984
KingsvilleTEXAS12013
RandadoTEXAS12017
Mirando CityTEXAS12025
EncinalTEXAS12006
George WestTEXAS12025
HondoTEXAS12016
El IndioTEXAS12007
Catarina 2TEXAS12017
GuerraTEXAS12023
Encinal 2TEXAS12024
SejitaTEXAS12024
MillettTEXAS12010

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