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

Chihuahuan Raven In Tamaulipan Brushlands

All regionsTamaulipan BrushlandsGeneralists

Chihuahuan Raven in Tamaulipan Brushlands has collapsed: down 90% on the route-weighted index since 1969.

-90%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 →
20Routes 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 →

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 →

Chihuahuan Raven has collapsed in Tamaulipan Brushlands: down 90% on the route-weighted index since 1969.

Chihuahuan Raven In Tamaulipan Brushlands Population Forecast

If the recent trend holds, Chihuahuan Raven in Tamaulipan Brushlands is projected to fall about 100% by 2029 — from 0.33 in 2024 to a central estimate of 0.00 (95% range 0.00–7.1). A 5-year backtest shows a typical error of ±27.1%, with 100% of held-out values landing inside the 95% band.

-100%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 →
0.00Projected 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 →
0.00–7.195% 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 →
±27.1%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, Chihuahuan Raven in Tamaulipan Brushlands is projected to fall about 100% by 2029 — from 0.33 in 2024 to a central estimate of 0.00 (95% range 0.00–7.1). A 5-year backtest shows a typical error of ±27.1%, 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 →
20250.280.007.4
20260.120.007.2
20270.000.007.1
20280.000.007.1
20290.000.007.1

Routes In Tamaulipan Brushlands

Routes recording Chihuahuan Raven 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 →
LaredoTEXAS102023
Catarina 2TEXAS92017
CatarinaTEXAS62010
Pedro CreekTEXAS52005
RandadoTEXAS42009
Agua NuevaTEXAS32012
ZapataTEXAS31982
San YgnacioTEXAS31985
RachalTEXAS21969
Mirando CityTEXAS22021
La PryorTEXAS21971
El SauzTEXAS22014
Encinal 2TEXAS22024
Catarina 3TEXAS22024
MillettTEXAS21997
Cavasara Cr.TEXAS22023
EncinalTEXAS12010
El IndioTEXAS12007
GuerraTEXAS12023
SejitaTEXAS12019

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