BirdAnalyst
Species · BCR 10 · BBS 2025 Release · 1966–2024

Plumbeous Vireo In Northern Rockies

All regionsNorthern RockiesForest birds

Plumbeous Vireo in Northern Rockies has collapsed: down 87% on the route-weighted index since 1974.

-87%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 →
38Routes 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 →
44YearsYears 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 collapsed in Northern Rockies: down 87% on the route-weighted index since 1974.

Plumbeous Vireo In Northern Rockies Population Forecast

If the recent trend holds, Plumbeous Vireo in Northern Rockies is projected to stay roughly flat through 2029, near 0.00 (95% range 0.00–0.54). A 5-year backtest shows a typical error of ±78.8%, with 100% of held-out values landing inside the 95% band.

n/aChange 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 →
0.00Projected 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 →
0.00–0.5495% 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 →
±78.8%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 Northern Rockies is projected to stay roughly flat through 2029, near 0.00 (95% range 0.00–0.54). A 5-year backtest shows a typical error of ±78.8%, with 100% of held-out values landing inside the 95% band.19722029
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 →
20250.000.000.54
20260.000.000.54
20270.000.000.54
20280.000.000.54
20290.000.000.54

Routes In Northern Rockies

Routes recording Plumbeous Vireo in Northern Rockies.
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 →
GlenMONTANA1501991
Red RockMONTANA51989
MooseWYOMING41991
CascadeIDAHO31983
SunbeamIDAHO31994
FeathervilleIDAHO31998
SaveryWYOMING31995
CentervilleIDAHO22015
CabartonIDAHO21995
Ne EntranceWYOMING21993
Hunter PeakWYOMING22004
MaybellCOLORADO12007
Great DivideCOLORADO11994
Browns ParkCOLORADO11997
Cape HornIDAHO11998
Yellow PineIDAHO11994
PolsonMONTANA12000
ArleeMONTANA12001
EllistonMONTANA11997
SulaMONTANA11997
ChestnutMONTANA12002
LaurelMONTANA12018
Wise RiverMONTANA11994
Saleratus CrUTAH12005
E. Bear LakeUTAH12022

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