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

Red Crossbill Population Trend in South Dakota

All statesForest birds

Red Crossbill in South Dakota has declined: down 27% on the route-weighted index since 1970.

-27%Since 1970TrendPercent 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 →
21Routes 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 Red Crossbill 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 →

No notable trend signals for Red Crossbill in South Dakota. See the full index history below.

Red Crossbill Population Forecast in South Dakota

If the recent trend holds, Red Crossbill in South Dakota is projected to rise about 160% by 2030 — from 2.2 in 2025 to a central estimate of 5.7 (95% range 0.00–16). A 5-year backtest shows a typical error of ±109.2%, with 100% of held-out values landing inside the 95% band.

+160%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 →
5.7Projected 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 →
0.00–1695% 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 →
±109.2%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, Red Crossbill in South Dakota is projected to rise about 160% by 2030 — from 2.2 in 2025 to a central estimate of 5.7 (95% range 0.00–16). A 5-year backtest shows a typical error of ±109.2%, with 100% of held-out values landing inside the 95% band.19682030
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 →
20265.80.0016
20275.80.0016
20285.70.0016
20295.70.0016
20305.70.0016

Red Crossbill Survey Routes in South Dakota

Routes recording Red Crossbill 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 →
Roubaix Lk7619911968
Black Fox5020171992
Norbeck4520021992
Rochford3320181992
Elk Mountain3020041992
Silver City2920121992
Pleasant Val2620241992
Wilmot2119701970
Long Draw1920251992
Lightning Cr1920251992
Englewood1520211992
Rosebud1419691969
Hazelrodt920251992
Hill City820131992
Wind Cave Np720251999
Custer520251968
Volunteer219681968
Rockyford120252025
Reva120161979
Ardmore119901984
Badlands120252025

Red Crossbill Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniacoloradogeorgiaidahoillinoismainemarylandmassachusettsmichiganminnesotamontananebraskanevadanew-hampshirenew-mexiconew-yorknorth-carolinanorth-dakotaoregonpennsylvaniasouth-carolinatennesseeutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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