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Species · Montana · BBS 2025 Release · 1966–2024

Marbled Godwit Population Trend in Montana

All statesShorebirds

Marbled Godwit in Montana has surged: up 445% on the route-weighted index since 1975.

+445%Since 1975TrendPercent 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 →
48Routes 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 →
51YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Marbled Godwit 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 →

Marbled Godwit has surged in Montana: up 445% on the route-weighted index since 1975.

Marbled Godwit Population Forecast in Montana

If the recent trend holds, Marbled Godwit in Montana is projected to stay roughly flat through 2029, near 1.3 (95% range 0.69–1.9). A 5-year backtest shows a typical error of ±24.7%, with 80% of held-out values landing inside the 95% band.

+8%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 →
1.3Projected 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 →
0.69–1.995% 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 →
±24.7%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, Marbled Godwit in Montana is projected to stay roughly flat through 2029, near 1.3 (95% range 0.69–1.9). A 5-year backtest shows a typical error of ±24.7%, with 80% 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 →
20251.20.601.8
20261.20.621.9
20271.30.641.9
20281.30.671.9
20291.30.691.9

Marbled Godwit Survey Routes in Montana

Routes recording Marbled Godwit 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 →
Malta1320241975
Flatwillow 21320132013
Virgelle1120241989
Ester Lake820242015
Saco720242015
Westby720242015
Oswego620241978
Chinook620242015
Dinosaurs H.M.620222018
Hay Lake520171989
Ingomar520241993
Shelby520242015
Gildford520242015
Jordan South520212017
Flatwillow420031976
Glentana420242015
Wolf Point420242015
Lindsay420242023
Lambert420232022
Glasgow320241982
Augusta320211979
Webster320242003
Great Falls220241972
Highwood220111990
Two Dot220232023

Marbled Godwit Population Trend in Other States

minnesotanevadanorth-dakotasouth-dakota

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