BirdAnalyst
Species · North Dakota · BBS 2026 Release · 1966–2025

Black Tern Population Trend in North Dakota

All statesWetland birds

Black Tern in North Dakota has increased: up 43% on the route-weighted index since 1969.

+43%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 →
38Routes 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 →
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 Black Tern 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 →

No notable trend signals for Black Tern in North Dakota. See the full index history below.

Black Tern Population Forecast in North Dakota

If the recent trend holds, Black Tern in North Dakota is projected to stay roughly flat through 2030, near 13 (95% range 3.5–22). A 5-year backtest shows a typical error of ±30.1%, with 60% of held-out values landing inside the 95% band.

+1%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 →
13Projected 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 →
3.5–2295% 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 →
±30.1%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, Black Tern in North Dakota is projected to stay roughly flat through 2030, near 13 (95% range 3.5–22). A 5-year backtest shows a typical error of ±30.1%, with 60% 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 →
2026123.021
2027123.121
2028123.221
2029123.422
2030133.522

Black Tern Survey Routes in North Dakota

Routes recording Black Tern 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 →
Lakota 28920252010
Buchanan6220251967
Lakota5720091968
Wild Rose5020251982
Horsehead Lk4820251981
Rolla3720241969
Carpio2020231969
Denbigh1920251968
Niles1720251989
Cooperstown1220251969
Webster1120241989
Montpelier1020251990
Danzig 21020252019
Kempton919811976
Sheyenne Lk920251980
Braddock920231989
Danzig820111982
Lake George720231967
Turtle Mtns620241980
Edgeley420251982
Wimbledon420251989
Ft Yates419691969
Bowman420141967
Glen Ullin420152015
Parshall420131989

Black Tern Population Trend in Other States

californiacoloradoidahoillinoisindianaiowakansasmainemichiganminnesotamissourimontananebraskanevadanew-yorkohiooregonsouth-dakotatexasutahwashingtonwisconsinwyoming

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