BirdAnalyst
Species · BCR 9 · BBS 2025 Release · 1966–2024

Plumbeous Vireo In Great Basin

All regionsGreat BasinForest birds

Plumbeous Vireo in Great Basin has fallen sharply: down 52% on the route-weighted index since 1974.

-52%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 →
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 →
48YearsYears 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 →

Plumbeous Vireo has fallen sharply in Great Basin: down 52% on the route-weighted index since 1974.

Forecast

If the recent trend holds, Plumbeous Vireo in Great Basin is projected to rise about 158% by 2029 — from 0.06 in 2024 to a central estimate of 0.15 (95% range 0.00–0.30). A 5-year backtest shows a typical error of ±59.9%, with 100% of held-out values landing inside the 95% band.

+158%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 →
0.15Projected 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 →
0.00–0.3095% 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 →
±59.9%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, Plumbeous Vireo in Great Basin is projected to rise about 158% by 2029 — from 0.06 in 2024 to a central estimate of 0.15 (95% range 0.00–0.30). A 5-year backtest shows a typical error of ±59.9%, 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 →
20250.140.000.30
20260.140.000.30
20270.140.000.30
20280.150.000.30
20290.150.000.30

Routes In Great Basin

Routes recording Plumbeous 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 →
LeadoreIDAHO71982
Silver CityIDAHO31993
BerylUTAH32024
NewcastleUTAH32022
Deep SpringsCALIFORNIA22021
AlmoIDAHO21994
RanchograndeNEVADA22024
JarbidgeNEVADA22015
Carson RiverNEVADA22002
AustinNEVADA22018
Pine CreekUTAH22019
BentonCALIFORNIA12019
BodieCALIFORNIA12024
Crowley LakeCALIFORNIA11986
SquirrelIDAHO12000
SpringfieldIDAHO11980
Magic MtnIDAHO12015
PocatelloIDAHO11987
PrestonIDAHO11991
Sand PassNEVADA12011
Fish CreekNEVADA12021
Walker CanNEVADA12022
Toiyabe NfNEVADA12018
WillisNEVADA12019
Bald Mtn.NEVADA12024

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