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

Gray Vireo In Chihuahuan Desert

All regionsChihuahuan DesertForest birds

Gray Vireo in Chihuahuan Desert has surged: up 148% on the route-weighted index since 1994.

+148%Since 1994TrendPercent 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 →
13Routes 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 →
32YearsYears 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 increasecomputed 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 →

Gray Vireo has surged in Chihuahuan Desert: up 148% on the route-weighted index since 1994.

Gray Vireo In Chihuahuan Desert Population Forecast

If the recent trend holds, Gray Vireo in Chihuahuan Desert is projected to fall about 36% by 2029 — from 0.28 in 2024 to a central estimate of 0.18 (95% range 0.01–0.34). A 5-year backtest shows a typical error of ±101.6%, with 100% of held-out values landing inside the 95% band.

-36%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 →
0.18Projected 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 →
0.01–0.3495% 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 →
±101.6%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, Gray Vireo in Chihuahuan Desert is projected to fall about 36% by 2029 — from 0.28 in 2024 to a central estimate of 0.18 (95% range 0.01–0.34). A 5-year backtest shows a typical error of ±101.6%, with 100% of held-out values landing inside the 95% band.19682029
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 →
20250.170.010.34
20260.170.010.34
20270.180.010.34
20280.180.010.34
20290.180.010.34

Routes In Chihuahuan Desert

Routes recording Gray Vireo 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 →
Devils R CynTEXAS32024
ComstockTEXAS21996
PumpvilleTEXAS22024
Capitan Mtn.NEW-MEXICO12016
PinonNEW-MEXICO12024
QueenNEW-MEXICO12021
EscondidaNEW-MEXICO12022
LongfellowTEXAS12023
CastolonTEXAS12024
Ft. StocktonTEXAS12004
ToyahvaleTEXAS12006
MarfaTEXAS12024
Chisos BasinTEXAS12008

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