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

Red-necked Grebe Population Trend in North Dakota

All statesWetland birds

Red-necked Grebe in North Dakota has surged: up 26× on the route-weighted index since 1986.

26×Since 1986TrendPercent 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 →
14Routes 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 →
38YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Red-necked 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 →

Red-necked Grebe has surged in North Dakota: up 26× on the route-weighted index since 1986.

Red-necked Grebe Population Forecast in North Dakota

If the recent trend holds, Red-necked Grebe in North Dakota is projected to fall about 21% by 2029 — from 1.7 in 2024 to a central estimate of 1.4 (95% range 0.71–2.1). A 5-year backtest shows a typical error of ±34.6%, with 100% of held-out values landing inside the 95% band.

-21%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 →
1.4Projected 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 →
0.71–2.195% 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 →
±34.6%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, Red-necked Grebe in North Dakota is projected to fall about 21% by 2029 — from 1.7 in 2024 to a central estimate of 1.4 (95% range 0.71–2.1). A 5-year backtest shows a typical error of ±34.6%, with 100% of held-out values landing inside the 95% band.19812029
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 →
20251.30.601.9
20261.30.622.0
20271.30.652.0
20281.40.682.0
20291.40.712.1

Red-necked Grebe Survey Routes in North Dakota

Routes recording Red-necked 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 →
Turtle Mtns2420241981
Horsehead Lk1120242002
Rolla320242002
Lakota 2320242011
Denbigh320242011
Powers Lake220242019
Cooperstown220212021
Sheyenne Lk220191987
Lakota220092008
Forman120072004
Montpelier120232023
Wimbledon120222015
Webster120132012
Niles120241998

Red-necked Grebe Population Trend in Other States

alaskaidahominnesotamontanaoregonwashingtonwisconsinwyoming

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