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

Western Grebe Population Trend in North Dakota

All statesWetland birds

Western Grebe in North Dakota has surged: up 149% on the route-weighted index since 1988.

+149%Since 1988TrendPercent 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 →
22Routes 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 →
34YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Western 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 →

Western Grebe has surged in North Dakota: up 149% on the route-weighted index since 1988.

Western Grebe Population Forecast in North Dakota

If the recent trend holds, Western Grebe in North Dakota is projected to rise about 626% by 2029 — from 0.52 in 2024 to a central estimate of 3.8 (95% range 0.00–8.1). A 5-year backtest shows a typical error of ±207%, with 80% of held-out values landing inside the 95% band.

+626%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 →
3.8Projected 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 →
0.00–8.195% 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 →
±207%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, Western Grebe in North Dakota is projected to rise about 626% by 2029 — from 0.52 in 2024 to a central estimate of 3.8 (95% range 0.00–8.1). A 5-year backtest shows a typical error of ±207%, with 80% of held-out values landing inside the 95% band.19862029
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 →
20253.50.007.8
20263.60.007.9
20273.60.008.0
20283.70.008.0
20293.80.008.1

Western Grebe Survey Routes in North Dakota

Routes recording Western 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 →
Lakota1220051997
Braddock1020221988
Douglas Crk720191987
Lake George520141997
Cooperstown520231999
Forman419971997
Danzig420142000
Buchanan420242011
Danzig 2420232019
Horsehead Lk320241996
Wild Rose320242004
Lakota 2220242011
Wimbledon120172016
Niles120002000
Tobacco119961995
Denbigh120242014
Bowman120192001
Gorham119971997
Bentley120112011
Powers Lake120231997
Sheyenne Lk120241986
Turtle Mtns119871987

Western Grebe Population Trend in Other States

arizonacaliforniacoloradoidahokansasminnesotamontananebraskanevadanew-mexicooregonsouth-dakotautahwashingtonwyoming

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