BirdAnalyst
Species · BCR 9 · BBS 2026 Release · 1966–2025

Gray Vireo In Great Basin

All regionsGreat BasinForest birds

Gray Vireo in Great Basin has surged: up 272% on the route-weighted index since 1998.

+272%Since 1998TrendPercent 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 →
26YearsYears 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 →

No notable trend signals for Gray Vireo in Great Basin. See the full index history below.

Gray Vireo In Great Basin Population Forecast

If the recent trend holds, Gray Vireo in Great Basin is projected to fall about 12% by 2030 — from 0.16 in 2025 to a central estimate of 0.14 (95% range 0.05–0.24). A 5-year backtest shows a typical error of ±55.1%, with 100% of held-out values landing inside the 95% band.

-12%Change by 2030TrendPercent 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 →
0.14Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.05–0.2495% 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 →
±55.1%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 Great Basin is projected to fall about 12% by 2030 — from 0.16 in 2025 to a central estimate of 0.14 (95% range 0.05–0.24). A 5-year backtest shows a typical error of ±55.1%, with 100% of held-out values landing inside the 95% band.19962030
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 →
20260.130.030.22
20270.130.030.22
20280.130.040.23
20290.140.040.23
20300.140.050.24

Routes In Great Basin

Routes recording Gray Vireo in Great Basin.
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 →
Meadow VallyNEVADA62025
BerylUTAH62025
VernonUTAH62025
NewcastleUTAH22025
WillisNEVADA12021
Comins LakeNEVADA12013
Gold HillUTAH12025
Indian PeakUTAH12006
Jericho JunctionUTAH12023
Tule ValleyUTAH12012

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.