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

Swainson's Hawk Population Trend in North Dakota

All statesBirds of prey

Swainson's Hawk in North Dakota has surged: up 133% on the route-weighted index since 1969.

+133%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 →
48Routes 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 Swainson's Hawk 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 →

Swainson's Hawk has surged in North Dakota: up 133% on the route-weighted index since 1969.

Swainson's Hawk Population Forecast in North Dakota

If the recent trend holds, Swainson's Hawk in North Dakota is projected to stay roughly flat through 2030, near 1.7 (95% range 0.89–2.5). A 5-year backtest shows a typical error of ±19.2%, with 100% of held-out values landing inside the 95% band.

+5%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 →
1.7Projected 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 →
0.89–2.595% 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 →
±19.2%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, Swainson's Hawk in North Dakota is projected to stay roughly flat through 2030, near 1.7 (95% range 0.89–2.5). A 5-year backtest shows a typical error of ±19.2%, with 100% 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 →
20261.60.832.4
20271.60.852.4
20281.60.862.4
20291.70.882.4
20301.70.892.5

Swainson's Hawk Survey Routes in North Dakota

Routes recording Swainson's Hawk 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 →
Edgeley620251980
Gorham520251968
Lake George420231969
Horsehead Lk420251980
Carson420251988
Regan420251974
Golva420251979
Montpelier420221991
Dunn Center320251968
Glen Ullin320231986
Emerado220251976
Lakota220041979
Ft Yates220041971
Dickinson220251968
Tobacco220021968
Bowman220251968
Zap220241979
Cedar Creek220221971
Powers Lake220241982
Braddock220231988
Solen220252005
Forman120241979
Walcott119921981
Sydney119831970
Danzig120141982

Swainson's Hawk Population Trend in Other States

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