BirdAnalyst
Species · North Dakota · BBS 2025 Release · 1966–2024

Pied-billed Grebe Population Trend in North Dakota

All statesWetland birds

Pied-billed Grebe in North Dakota has surged: up 143% on the route-weighted index since 1969.

+143%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 →
42Routes 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 Pied-billed Grebe Trends in North DakotaNotable 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 →

Pied-billed Grebe has surged in North Dakota: up 143% on the route-weighted index since 1969.

Pied-billed Grebe Population Forecast in North Dakota

If the recent trend holds, Pied-billed Grebe in North Dakota is projected to stay roughly flat through 2029, near 3.5 (95% range 0.84–6.1). A 5-year backtest shows a typical error of ±27.4%, with 100% of held-out values landing inside the 95% band.

+7%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 →
3.5Projected 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 →
0.84–6.195% 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, Pied-billed Grebe in North Dakota is projected to stay roughly flat through 2029, near 3.5 (95% range 0.84–6.1). 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 →
20253.30.696.0
20263.40.736.0
20273.40.776.1
20283.40.816.1
20293.50.846.1

Pied-billed Grebe Survey Routes in North Dakota

Routes recording Pied-billed Grebe in North Dakota.
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 →
Buchanan2620241967
Horsehead Lk1320241980
Danzig 21020242019
Lakota920091968
Forman820241969
Wimbledon820241981
Wild Rose620241982
Lake George320191967
Danzig320131982
Webster320231995
Niles320241992
Carpio320141970
Denbigh320241969
Powers Lake320231985
Douglas Crk320231983
Montpelier320241991
Lakota 2320242010
Cooperstown220241969
Nash219961989
Walcott120142001
Sydney119831969
Edgeley120241995
Kempton119961996
Emerado120131980
Bowesmont119961971

Pied-billed Grebe Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinaohiooklahomaoregonpennsylvaniasouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwisconsinwyoming

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