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Species · Montana · BBS 2026 Release · 1966–2025

Orange-crowned Warbler Population Trend in Montana

All statesForest birds

Orange-crowned Warbler in Montana has risen sharply: up 55% on the route-weighted index since 1970.

+55%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 →
40Routes 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 Orange-crowned Warbler 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 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 →

Orange-crowned Warbler has risen sharply in Montana: up 55% on the route-weighted index since 1970.

Orange-crowned Warbler Population Forecast in Montana

If the recent trend holds, Orange-crowned Warbler in Montana is projected to rise about 103% by 2030 — from 0.43 in 2025 to a central estimate of 0.88 (95% range 0.45–1.3). A 5-year backtest shows a typical error of ±80.9%, with 40% of held-out values landing inside the 95% band.

+103%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 →
0.88Projected 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 →
0.45–1.395% 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 →
±80.9%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, Orange-crowned Warbler in Montana is projected to rise about 103% by 2030 — from 0.43 in 2025 to a central estimate of 0.88 (95% range 0.45–1.3). A 5-year backtest shows a typical error of ±80.9%, with 40% of held-out values landing inside the 95% band.19682030
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 →
20260.850.421.3
20270.850.431.3
20280.860.431.3
20290.870.441.3
20300.880.451.3

Orange-crowned Warbler Survey Routes in Montana

Routes recording Orange-crowned Warbler 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 →
Arlee820251977
St Regis620251978
Whitefish Lake620242016
Threemile Wa420251993
Pryor Mtn.420252000
Polson420191991
Inside Road420251990
Greenoagh 3420252015
Cramer Creek320192010
East Glacier Park320232015
Ninemile320251993
Skalkaho319951993
Kalispell220231968
Woodman220231976
Sula220231988
Skalkho-Rye220222006
Swan Lake220242017
Painted Rock220041993
Libby Dam120131979
St Mary120031979
Logan Pass120241988
Victor120231994
Greenough120031996
Elevation Mt120242003
Clinton120111976

Orange-crowned Warbler Population Trend in Other States

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