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

Loggerhead Shrike Population Trend in South Dakota

All statesGeneralists

Loggerhead Shrike in South Dakota has fallen sharply: down 54% on the route-weighted index since 1969.

-54%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 Loggerhead Shrike 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 declinecomputed 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 →

Loggerhead Shrike has fallen sharply in South Dakota: down 54% on the route-weighted index since 1969.

Loggerhead Shrike Population Forecast in South Dakota

If the recent trend holds, Loggerhead Shrike in South Dakota is projected to fall about 77% by 2029 — from 0.77 in 2024 to a central estimate of 0.18 (95% range 0.00–0.99). A 5-year backtest shows a typical error of ±74.7%, with 100% of held-out values landing inside the 95% band.

-77%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 →
0.18Projected 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 →
0.00–0.9995% 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 →
±74.7%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, Loggerhead Shrike in South Dakota is projected to fall about 77% by 2029 — from 0.77 in 2024 to a central estimate of 0.18 (95% range 0.00–0.99). A 5-year backtest shows a typical error of ±74.7%, 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 →
20250.280.001.1
20260.260.001.1
20270.230.001.0
20280.210.001.0
20290.180.000.99

Loggerhead Shrike Survey Routes in South Dakota

Routes recording Loggerhead Shrike 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 →
Isabel2620151990
Eagle Butte2220151990
Gorman919991992
Reva820241979
Maurine720241968
Marcus420131999
Promise320001971
Railroad Butte320222003
Chamberlain220101969
Rosebud220091967
Volga219791971
Raymond220051969
Crow Creek220181968
Gettysburg219941976
Laplant220131971
Ottumwa220221967
Fort Pierre220151969
Lacreek220231991
Cottonwood220231997
Lennox119921969
Tripp120001967
Howard119711971
White Lake120111967
Geddes120171967
Winner120241968

Loggerhead Shrike Population Trend in Other States

alabamaarizonaarkansascaliforniacoloradofloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmichiganminnesotamississippimissourimontananebraskanevadanew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniasouth-carolinatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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