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

Swamp Sparrow Population Trend in South Dakota

All statesGeneralists

Swamp Sparrow in South Dakota has surged: up 110% on the route-weighted index since 1971.

+110%Since 1971
10Routes In State
39Years

Notable Swamp Sparrow Trends in South Dakota

long arc increasecomputed index

Swamp Sparrow has surged in South Dakota: up 110% on the route-weighted index since 1971.

Swamp Sparrow Population Forecast in South Dakota

If the recent trend holds, Swamp Sparrow in South Dakota is projected to fall about 68% by 2029 — from 0.27 in 2024 to a central estimate of 0.09 (95% range 0.00–0.22). A 5-year backtest shows a typical error of ±79%, with 60% of held-out values landing inside the 95% band.

-68%Change by 2029
0.09Projected 2029 index
0.00–0.2295% range
±79%Backtest error
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 index95% low95% high
20250.090.000.23
20260.090.000.23
20270.090.000.23
20280.090.000.22
20290.090.000.22

Swamp Sparrow Survey Routes in South Dakota

Routes recording Swamp Sparrow in South Dakota.
Lennox320241973
Veblen320222006
Howard220191979
Volga220241967
Roswell119911971
Broadland120022000
Lacreek120232017
Wilmot120242017
Britton119671967
Forbes120222004

Swamp Sparrow Population Trend in Other States

connecticutdelawareillinoisindianaiowamainemarylandmassachusettsmichiganminnesotanebraskanew-hampshirenew-jerseynew-yorknorth-dakotaohiopennsylvaniarhode-islandvermontvirginiawest-virginiawisconsin

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