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

Harris's Hawk In Tamaulipan Brushlands

All regionsTamaulipan BrushlandsBirds of prey

Harris's Hawk in Tamaulipan Brushlands has fallen sharply: down 66% on the route-weighted index since 1969.

-66%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 →

Harris's Hawk has fallen sharply in Tamaulipan Brushlands: down 66% on the route-weighted index since 1969.

Harris's Hawk In Tamaulipan Brushlands Population Forecast

If the recent trend holds, Harris's Hawk in Tamaulipan Brushlands is projected to rise about 50% by 2030 — from 1.5 in 2025 to a central estimate of 2.2 (95% range 0.00–4.7). A 5-year backtest shows a typical error of ±29.8%, with 100% of held-out values landing inside the 95% band.

+50%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 →
2.2Projected 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 →
0.00–4.795% 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 →
±29.8%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, Harris's Hawk in Tamaulipan Brushlands is projected to rise about 50% by 2030 — from 1.5 in 2025 to a central estimate of 2.2 (95% range 0.00–4.7). A 5-year backtest shows a typical error of ±29.8%, 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 →
20262.30.004.9
20272.30.004.8
20282.30.004.8
20292.20.004.8
20302.20.004.7

Routes In Tamaulipan Brushlands

Routes recording Harris'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 →
Millett 2TEXAS132024
Agua NuevaTEXAS112023
ZapataTEXAS101987
Encinal 2TEXAS82025
EncinalTEXAS42010
SejitaTEXAS42023
LaredoTEXAS42023
MillettTEXAS42012
Pedro CreekTEXAS42005
San YgnacioTEXAS31985
George WestTEXAS32018
KingsvilleTEXAS22023
Mirando CityTEXAS22025
CatarinaTEXAS22010
El IndioTEXAS22007
RaymondvilleTEXAS22009
DilleyTEXAS22025
GuerraTEXAS22025
Catarina 3TEXAS22025
ProgresoTEXAS22009
RachalTEXAS12023
RandadoTEXAS12022
La PryorTEXAS12017
HondoTEXAS12019
El SauzTEXAS12013

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