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

Mountain Bluebird Population Trend in North Dakota

All statesForest birds

Mountain Bluebird in North Dakota has surged: up 317% on the route-weighted index since 1974.

+317%Since 1974TrendPercent 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 →
11Routes 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 →
45YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Mountain Bluebird 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 →

Mountain Bluebird has surged in North Dakota: up 317% on the route-weighted index since 1974.

Mountain Bluebird Population Forecast in North Dakota

If the recent trend holds, Mountain Bluebird in North Dakota is projected to stay roughly flat through 2027, near 0.41 (95% range 0.00–0.87). A 5-year backtest shows a typical error of ±251.6%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2027TrendPercent 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 →
0.41Projected 2027 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.00–0.8795% 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 →
±251.6%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, Mountain Bluebird in North Dakota is projected to stay roughly flat through 2027, near 0.41 (95% range 0.00–0.87). A 5-year backtest shows a typical error of ±251.6%, with 100% of held-out values landing inside the 95% band.19712027
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 →
20230.390.000.85
20240.400.000.85
20250.400.000.86
20260.410.000.86
20270.410.000.87

Mountain Bluebird Survey Routes in North Dakota

Routes recording Mountain Bluebird 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 →
Roosevelt Pk620191982
Tobacco320191971
Turtle Mtns220001994
Gorham120131991
Golva120081986
Dickinson119911989
Carpio120101999
Loraine119921992
Stanley120221988
Denbigh119951993
Zap119981998

Mountain Bluebird Population Trend in Other States

alaskaarizonacaliforniacoloradoidahomontananebraskanevadanew-mexicooregonsouth-dakotautahwashingtonwyoming

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