BirdAnalyst
Species · Montana · BBS 2025 Release · 1966–2024

Red-eyed Vireo Population Trend in Montana

All statesForest birds

Red-eyed Vireo in Montana has fallen sharply: down 54% on the route-weighted index since 1970.

-54%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 →
41Routes In StateSurvey 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 Red-eyed Vireo Trends in MontanaNotable 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 →

Red-eyed Vireo has fallen sharply in Montana: down 54% on the route-weighted index since 1970.

Red-eyed Vireo Population Forecast in Montana

If the recent trend holds, Red-eyed Vireo in Montana is projected to fall about 91% by 2029 — from 0.59 in 2024 to a central estimate of 0.05 (95% range 0.00–0.46). A 5-year backtest shows a typical error of ±78.7%, with 80% of held-out values landing inside the 95% band.

-91%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 →
0.05Projected 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 →
0.00–0.4695% 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 →
±78.7%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, Red-eyed Vireo in Montana is projected to fall about 91% by 2029 — from 0.59 in 2024 to a central estimate of 0.05 (95% range 0.00–0.46). A 5-year backtest shows a typical error of ±78.7%, 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 →
20250.090.000.49
20260.080.000.48
20270.070.000.47
20280.060.000.47
20290.050.000.46

Red-eyed Vireo Survey Routes in Montana

Routes recording Red-eyed Vireo in Montana.
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 →
Libby Dam1220241979
Swan Lake1020242017
Fish Creek1020241995
Ninemile720242004
Whitefish Lake520242019
Victor220231993
Willow Creek 2219821982
Woodman220241968
Two Dot219801980
Inside Road220241993
Red Rock219751975
Noxon220231995
Kalispell120231968
St Mary120081982
Cleveland119851981
Harlem119801980
St Regis120211980
Arlee120211968
Augusta120211978
Highwood119961972
Brusett119871986
Savage120211995
Clinton120241975
Elliston119981998
Forsyth120172001

Red-eyed Vireo Population Trend in Other States

alabamaalaskaarkansascoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourinebraskanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasvermontvirginiawashingtonwest-virginiawisconsinwyoming

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