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Species · BCR 11 · BBS 2026 Release · 1966–2025

Marbled Godwit In Prairie Potholes

All regionsPrairie PotholesShorebirds

Marbled Godwit in Prairie Potholes has risen sharply: up 70% on the route-weighted index since 1969.

+70%Since 1969TrendPercent 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 →
82Routes 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 →
58YearsYears 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 →

Marbled Godwit has risen sharply in Prairie Potholes: up 70% on the route-weighted index since 1969.

Marbled Godwit In Prairie Potholes Population Forecast

If the recent trend holds, Marbled Godwit in Prairie Potholes is projected to rise about 36% by 2030 — from 2.1 in 2025 to a central estimate of 2.9 (95% range 1.8–4.0). A 5-year backtest shows a typical error of ±34%, with 100% of held-out values landing inside the 95% band.

+36%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 →
2.9Projected 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 →
1.8–4.095% 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 →
±34%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 Prairie Potholes is projected to rise about 36% by 2030 — from 2.1 in 2025 to a central estimate of 2.9 (95% range 1.8–4.0). A 5-year backtest shows a typical error of ±34%, with 100% of held-out values landing inside the 95% band.19672030
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 →
20262.81.73.9
20272.81.73.9
20282.81.73.9
20292.91.84.0
20302.91.84.0

Routes In Prairie Potholes

Routes recording Marbled Godwit in Prairie Potholes.
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 →
Horsehead LkNORTH-DAKOTA222025
GryglaMINNESOTA152016
GlasgowMONTANA152025
Ester LakeMONTANA142025
SacoMONTANA132025
WestbyMONTANA122025
BraddockNORTH-DAKOTA112023
GormanSOUTH-DAKOTA112010
VirgelleMONTANA102025
ChinookMONTANA82025
WalcottNORTH-DAKOTA82015
OswegoMONTANA72025
ShelbyMONTANA72025
White LakeSOUTH-DAKOTA72011
Douglas CrkNORTH-DAKOTA62025
Lake BronsonMINNESOTA52011
Hay LakeMONTANA52017
RedstoneMONTANA52025
GildfordMONTANA52025
GlentanaMONTANA52025
RaymondSOUTH-DAKOTA52021
GettysburgSOUTH-DAKOTA52023
Great FallsMONTANA42025
Wolf PointMONTANA42024
LambertMONTANA42023

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