BirdAnalyst
Species · Montana · BBS 2026 Release · 1966–2025

Long-billed Curlew Population Trend in Montana

All statesShorebirds

Long-billed Curlew in Montana has surged: up 378% on the route-weighted index since 1970.

+378%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 →
79Routes 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 →
57YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Long-billed Curlew 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 →

Long-billed Curlew has surged in Montana: up 378% on the route-weighted index since 1970.

Long-billed Curlew Population Forecast in Montana

If the recent trend holds, Long-billed Curlew in Montana is projected to stay roughly flat through 2030, near 4.1 (95% range 2.4–5.7). A 5-year backtest shows a typical error of ±23.3%, with 80% of held-out values landing inside the 95% band.

-7%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 →
4.1Projected 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 →
2.4–5.795% 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 →
±23.3%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, Long-billed Curlew in Montana is projected to stay roughly flat through 2030, near 4.1 (95% range 2.4–5.7). A 5-year backtest shows a typical error of ±23.3%, with 80% 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 →
20263.92.35.5
20273.92.35.5
20284.02.45.6
20294.02.45.6
20304.12.45.7

Long-billed Curlew Survey Routes in Montana

Routes recording Long-billed Curlew 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 →
Roy2920251991
Red Rock2920231973
Roundup2820252016
Shawmut2720251979
Boulder2620241969
Glen2020251977
Heart Butte1720252015
Winnett1620252017
Wheat Basin1620252017
Winifred1420232023
Winifred 21420252024
Two Dot1320251976
Church Hill1320252017
Hehn Draw1120252016
Flatwillow1020081968
Maynard Coulee1020252017
Redstone920251968
Glentana920252015
Augusta820251976
Flatwillow 2820232010
Saco820252015
Raynesford820252016
Muddy Creek820152015
Pryor Mtn.820252001
Great Falls720251973

Long-billed Curlew Population Trend in Other States

californiacoloradoidahokansasnebraskanevadanew-mexiconorth-dakotaoklahomaoregonsouth-dakotatexasutahwashingtonwyoming

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