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

Brewer's Blackbird Population Trend in North Dakota

All statesGeneralists

Brewer's Blackbird in North Dakota has surged: up 236% on the route-weighted index since 1969.

+236%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 →
51Routes 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 Brewer's Blackbird 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 →

Brewer's Blackbird has surged in North Dakota: up 236% on the route-weighted index since 1969.

Brewer's Blackbird Population Forecast in North Dakota

If the recent trend holds, Brewer's Blackbird in North Dakota is projected to rise about 15% by 2030 — from 13 in 2025 to a central estimate of 15 (95% range 8.6–21). A 5-year backtest shows a typical error of ±19%, with 100% of held-out values landing inside the 95% band.

+15%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 →
15Projected 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 →
8.6–2195% 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%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, Brewer's Blackbird in North Dakota is projected to rise about 15% by 2030 — from 13 in 2025 to a central estimate of 15 (95% range 8.6–21). A 5-year backtest shows a typical error of ±19%, 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 →
2026148.021
2027158.121
2028158.321
2029158.521
2030158.621

Brewer's Blackbird Survey Routes in North Dakota

Routes recording Brewer's Blackbird 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 →
Abercrombie 28220172013
Denbigh6220251968
Wild Rose4820251982
Horsehead Lk3320251981
Bowesmont 22720162015
Solen2720252005
Danzig 22420252019
Carpio2320231967
Ft Yates2020041970
Buchanan1920251976
Gorham1920251968
Glen Ullin1920251982
Zap1420241967
Golva1320251979
Montpelier1320011990
Dunn Center1220251968
Powers Lake1220251980
Roosevelt Pk1120191982
Parshall1120111982
Loraine1020191982
Sheyenne Lk1020251982
Turtle Mtns1020251983
Cooperstown920251970
Dickinson920251968
Kempton820171971

Brewer's Blackbird Population Trend in Other States

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