BirdAnalyst
Species · BCR 16 · BBS 2025 Release · 1966–2024

Gray Vireo In Southern Rockies / Colorado Plateau

All regionsSouthern Rockies / Colorado PlateauForest birds

Gray Vireo in Southern Rockies / Colorado Plateau has surged: up 96% on the route-weighted index since 1970.

+96%Since 1970TrendPercent 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 →
85Routes 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 →
56YearsYears 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 Southern Rockies / Colorado Plateau: up 96% on the route-weighted index since 1970.

Gray Vireo In Southern Rockies / Colorado Plateau Population Forecast

If the recent trend holds, Gray Vireo in Southern Rockies / Colorado Plateau is projected to stay roughly flat through 2029, near 0.83 (95% range 0.43–1.2). A 5-year backtest shows a typical error of ±20.1%, with 80% of held-out values landing inside the 95% band.

+3%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 →
0.83Projected 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 →
0.43–1.295% 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 →
±20.1%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, Gray Vireo in Southern Rockies / Colorado Plateau is projected to stay roughly flat through 2029, near 0.83 (95% range 0.43–1.2). A 5-year backtest shows a typical error of ±20.1%, with 80% 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 →
20250.790.391.2
20260.800.401.2
20270.810.411.2
20280.820.421.2
20290.830.431.2

Routes In Southern Rockies / Colorado Plateau

Routes recording Gray Vireo in Southern Rockies / Colorado Plateau.
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 →
ShivwitzUTAH192024
Moquith MtnUTAH152024
House RockARIZONA112022
ToroweapARIZONA112024
La Plata 2NEW-MEXICO102016
AltonahUTAH81969
CanyonlandsUTAH82024
AnimasCOLORADO72004
The GapARIZONA61973
Peach SpringARIZONA62024
Glen CanyonUTAH62024
RosevaleCOLORADO52023
Mesaverde NpCOLORADO52024
NotomUTAH52019
BlandingUTAH52024
McgaffeyNEW-MEXICO42023
La PlataNEW-MEXICO42013
HiteUTAH42023
La Sal 3UTAH42024
Blackhead PkCOLORADO32000
Baxter PassCOLORADO32024
AngoraCOLORADO32024
Salt Lake 2NEW-MEXICO32024
EscalanteUTAH32018
Rose WellsARIZONA21969

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