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

Warbling Vireo In Northern Rockies

All regionsNorthern RockiesForest birds

Warbling Vireo in Northern Rockies has surged: up 85% on the route-weighted index since 1970.

+85%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 →
191Routes 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 →

Warbling Vireo has surged in Northern Rockies: up 85% on the route-weighted index since 1970.

Warbling Vireo In Northern Rockies Population Forecast

If the recent trend holds, Warbling Vireo in Northern Rockies is projected to stay roughly flat through 2029, near 9.8 (95% range 7.8–12). A 5-year backtest shows a typical error of ±17.3%, with 40% of held-out values landing inside the 95% band.

-2%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 →
9.8Projected 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 →
7.8–1295% 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 →
±17.3%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, Warbling Vireo in Northern Rockies is projected to stay roughly flat through 2029, near 9.8 (95% range 7.8–12). A 5-year backtest shows a typical error of ±17.3%, with 40% 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 →
20259.57.512
20269.67.612
20279.77.612
20289.77.712
20299.87.812

Routes In Northern Rockies

Routes recording Warbling 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 →
ClancyMONTANA512023
Fish CreekMONTANA502024
CascadeIDAHO491984
ArleeMONTANA432024
AlpineWYOMING432024
Hunter PeakWYOMING422024
Rochat DivdeIDAHO382023
Wise RiverMONTANA382024
Colter Bay 2WYOMING362024
ChallisIDAHO342024
CabartonIDAHO342023
Cramer CreekMONTANA342019
MammothWYOMING342024
SulaMONTANA332024
LimaMONTANA332024
Pryor Mtn.MONTANA332024
Soda LakeWYOMING332024
Cape HornIDAHO322024
Hebgen LakeMONTANA322024
Logan PassMONTANA322024
N Fork Cda RIDAHO312019
ChestnutMONTANA312024
SaveryWYOMING311995
WilsonWYOMING312024
Fiddler LkWYOMING312024

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