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

Mountain Bluebird Population Trend in South Dakota

All statesForest birds

Mountain Bluebird in South Dakota has surged: up 146% on the route-weighted index since 1969.

+146%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 →
23Routes 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 Mountain Bluebird Trends in South 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 South Dakota: up 146% on the route-weighted index since 1969.

Mountain Bluebird Population Forecast in South Dakota

If the recent trend holds, Mountain Bluebird in South Dakota is projected to rise about 27% by 2029 — from 1.8 in 2024 to a central estimate of 2.3 (95% range 1.0–3.6). A 5-year backtest shows a typical error of ±75.4%, with 80% of held-out values landing inside the 95% band.

+27%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 →
2.3Projected 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 →
1.0–3.695% 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 →
±75.4%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 South Dakota is projected to rise about 27% by 2029 — from 1.8 in 2024 to a central estimate of 2.3 (95% range 1.0–3.6). A 5-year backtest shows a typical error of ±75.4%, with 80% 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 →
20252.20.903.5
20262.20.933.5
20272.30.963.5
20282.30.993.6
20292.31.03.6

Mountain Bluebird Survey Routes in South Dakota

Routes recording Mountain Bluebird in South 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 →
Custer2020241968
Lightning Cr1720221992
Elk Mountain1620041992
Rochford1120181992
Pleasant Val1020241992
Hill City1020131992
Rockyford819751967
Englewood620211992
Wind Cave Np520241999
Roubaix Lk519911967
Black Fox520171992
Hazelrodt520241992
Silver City320121992
S. Pioneer220102010
Laplant219901990
Reva220151985
Norbeck219931992
Promise120102010
Harding120102010
Cedar Pass120221968
Badlands120181982
White River120142014
Long Draw120231992

Mountain Bluebird Population Trend in Other States

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