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

Bell's Vireo In Chihuahuan Desert

All regionsChihuahuan DesertForest birds

Bell's Vireo in Chihuahuan Desert has surged: up 210% on the route-weighted index since 1969.

+210%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 →
40Routes 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 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 →

Bell's Vireo has surged in Chihuahuan Desert: up 210% on the route-weighted index since 1969.

Bell's Vireo In Chihuahuan Desert Population Forecast

If the recent trend holds, Bell's Vireo in Chihuahuan Desert is projected to rise about 32% by 2029 — from 5.4 in 2024 to a central estimate of 7.1 (95% range 5.2–9.1). A 5-year backtest shows a typical error of ±16.1%, with 100% of held-out values landing inside the 95% band.

+32%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 →
7.1Projected 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 →
5.2–9.195% 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 →
±16.1%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, Bell's Vireo in Chihuahuan Desert is projected to rise about 32% by 2029 — from 5.4 in 2024 to a central estimate of 7.1 (95% range 5.2–9.1). A 5-year backtest shows a typical error of ±16.1%, 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 →
20256.74.88.7
20266.84.98.8
20276.95.08.9
20287.05.19.0
20297.15.29.1

Routes In Chihuahuan Desert

Routes recording Bell's 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 →
LongfellowTEXAS392024
OzonaTEXAS372022
ComstockTEXAS352023
Devils R CynTEXAS252024
Red RockNEW-MEXICO202024
PumpvilleTEXAS192024
Dove Mtn.TEXAS162006
Casa PiedraTEXAS132023
Quitman Cyn.TEXAS132009
LangtryTEXAS112000
Bear MtnTEXAS102024
Coyanda DrawTEXAS92024
AltudaTEXAS72023
ToyahvaleTEXAS62024
ShafterTEXAS51985
CastolonTEXAS52024
Ft. DavisTEXAS52023
RodeoNEW-MEXICO42024
LaborcitaNEW-MEXICO42019
MarathonTEXAS42023
Hatchet PeakNEW-MEXICO32024
ColumbusNEW-MEXICO32024
Delaware CrkTEXAS32015
Ft. StocktonTEXAS32024
Sierra BlancTEXAS32024

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