BirdAnalyst
Species · Texas · BBS 2025 Release · 1966–2024

Harris's Hawk Population Trend in Texas

All statesGeneralists

Harris's Hawk in Texas has fallen sharply: down 68% on the route-weighted index since 1969.

-68%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 →
62Routes In StateSurvey 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 Harris's Hawk Trends in TexasNotable 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 Texas: down 68% on the route-weighted index since 1969.

Harris's Hawk Population Forecast in Texas

If the recent trend holds, Harris's Hawk in Texas is projected to fall about 17% by 2029 — from 0.25 in 2024 to a central estimate of 0.21 (95% range 0.00–0.53). A 5-year backtest shows a typical error of ±13%, with 100% of held-out values landing inside the 95% band.

-17%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 →
0.21Projected 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 →
0.00–0.5395% 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 →
±13%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 Texas is projected to fall about 17% by 2029 — from 0.25 in 2024 to a central estimate of 0.21 (95% range 0.00–0.53). A 5-year backtest shows a typical error of ±13%, 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 →
20250.230.000.56
20260.230.000.55
20270.220.000.55
20280.220.000.54
20290.210.000.53

Harris's Hawk Survey Routes in Texas

Routes recording Harris's Hawk in Texas.
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 21320242013
Agua Nueva1120231969
Zapata1019871967
Encinal 2820242011
Dilley820242018
Loyola Beach 2620172010
Loyola Beach620091994
Catarina 3520242018
Encinal420101969
Sejita420231994
Laredo420231994
Millett420121995
Pedro Creek420051996
San Ygnacio319851967
George West320181968
Adamsville319771977
Langtry319951995
Wink319811978
Lag Atascosa220241993
Kingsville220231967
Petronila219921992
Mirando City220241969
L. Atascosa Nwr220221998
Campbellton220191984
Catarina220101970

Harris's Hawk Population Trend in Other States

arizonacalifornianew-mexico

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