BirdAnalyst
Species · BCR 35 · BBS 2025 Release · 1966–2024

Hepatic Tanager In Chihuahuan Desert

All regionsChihuahuan DesertGeneralists

Hepatic Tanager in Chihuahuan Desert has collapsed: down 78% on the route-weighted index since 1974.

-78%Since 1974TrendPercent 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 →
10Routes 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 →
46YearsYears 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 →

Hepatic Tanager has collapsed in Chihuahuan Desert: down 78% on the route-weighted index since 1974.

Hepatic Tanager In Chihuahuan Desert Population Forecast

If the recent trend holds, Hepatic Tanager in Chihuahuan Desert is projected to rise about 358% by 2029 — from 0.07 in 2024 to a central estimate of 0.32 (95% range 0.00–0.69). A 5-year backtest shows a typical error of ±860%, with 0% of held-out values landing inside the 95% band.

+358%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 →
0.32Projected 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 →
0.00–0.6995% 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 →
±860%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, Hepatic Tanager in Chihuahuan Desert is projected to rise about 358% by 2029 — from 0.07 in 2024 to a central estimate of 0.32 (95% range 0.00–0.69). A 5-year backtest shows a typical error of ±860%, with 0% of held-out values landing inside the 95% band.19702029
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 →
20250.310.000.68
20260.310.000.68
20270.320.000.69
20280.320.000.69
20290.320.000.69

Routes In Chihuahuan Desert

Routes recording Hepatic Tanager in Chihuahuan Desert.
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 →
Capitan Mtn.NEW-MEXICO32017
Bear MtnTEXAS32012
CloudcroftNEW-MEXICO22017
CarrizozoNEW-MEXICO12024
PinonNEW-MEXICO12024
QueenNEW-MEXICO12021
ValentineTEXAS11987
ToyahvaleTEXAS12013
Salt FlatTEXAS12014
Chisos BasinTEXAS12023

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