BirdAnalyst
Species · BCR 11 · BBS 2025 Release · 1966–2024

Marbled Godwit In Prairie Potholes

All regionsPrairie PotholesShorebirds

Marbled Godwit in Prairie Potholes has risen sharply: up 71% on the route-weighted index since 1969.

+71%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 →
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 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 71% 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 45% by 2029 — from 2.0 in 2024 to a central estimate of 2.9 (95% range 1.8–4.0). A 5-year backtest shows a typical error of ±27.4%, with 100% of held-out values landing inside the 95% band.

+45%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 →
2.9Projected 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 →
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 →
±27.4%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 45% by 2029 — from 2.0 in 2024 to a central estimate of 2.9 (95% range 1.8–4.0). A 5-year backtest shows a typical error of ±27.4%, with 100% of held-out values landing inside the 95% band.19672029
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 →
20252.81.73.9
20262.81.73.9
20272.91.84.0
20282.91.84.0
20292.91.84.0

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 →
GryglaMINNESOTA152016
MaltaMONTANA132024
VirgelleMONTANA112024
GormanSOUTH-DAKOTA112010
DenbighNORTH-DAKOTA102024
Danzig 2NORTH-DAKOTA102024
Ester LakeMONTANA82024
WalcottNORTH-DAKOTA82015
SacoMONTANA72024
WestbyMONTANA72024
Wild RoseNORTH-DAKOTA72024
Douglas CrkNORTH-DAKOTA72024
White LakeSOUTH-DAKOTA72011
OswegoMONTANA62024
ChinookMONTANA62024
Powers LakeNORTH-DAKOTA62024
BraddockNORTH-DAKOTA62022
Lake BronsonMINNESOTA52011
Hay LakeMONTANA52017
ShelbyMONTANA52024
GildfordMONTANA52024
Horsehead LkNORTH-DAKOTA52024
RaymondSOUTH-DAKOTA52021
GettysburgSOUTH-DAKOTA52023
GlentanaMONTANA42024

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