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

Brewer's Blackbird Population Trend in North Dakota

All statesGeneralists

Brewer's Blackbird in North Dakota has surged: up 207% on the route-weighted index since 1969.

+207%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 →
57YearsYears 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 207% 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 2029 — from 13 in 2024 to a central estimate of 15 (95% range 8.3–21). A 5-year backtest shows a typical error of ±24.3%, with 100% of held-out values landing inside the 95% band.

+15%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 →
15Projected 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 →
8.3–2195% 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 →
±24.3%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 2029 — from 13 in 2024 to a central estimate of 15 (95% range 8.3–21). A 5-year backtest shows a typical error of ±24.3%, with 100% of held-out values landing inside the 95% band.19672029
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 →
2025147.721
2026147.921
2027158.021
2028158.221
2029158.321

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 →
Denbigh8220241968
Abercrombie 28220172013
Wild Rose5020241982
Glen Ullin3220221982
Solen3220242005
Stanley2920241970
Danzig 22720242019
Bowesmont 22720162015
Carpio2320231967
Golva2220231979
Ft Yates2020041970
Dunn Center1920241968
Powers Lake1820241980
Zap1420241967
Regan1320221969
Sheyenne Lk1320241982
Turtle Mtns1320241983
Montpelier1320011990
Horsehead Lk1220241981
Roosevelt Pk1120191982
Parshall1120111982
Douglas Crk1120241982
Buchanan1020241976
Loraine1020191982
Kempton820171971

Brewer's Blackbird Population Trend in Other States

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