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

Forster's Tern Population Trend in South Dakota

All statesWetland birds

Forster's Tern in South Dakota has edged down: down 21% on the route-weighted index since 1969.

-21%Since 1969
15Routes In State
38Years

Notable Forster's Tern Trends in South Dakota

No notable trend signals for Forster's Tern in South Dakota. See the full index history below.

Forster's Tern Population Forecast in South Dakota

If the recent trend holds, Forster's Tern in South Dakota is projected to stay roughly flat through 2029, near 0.06 (95% range 0.00–0.17). A 5-year backtest shows a typical error of ±35.8%, with 100% of held-out values landing inside the 95% band.

n/aChange by 2029
0.06Projected 2029 index
0.00–0.1795% range
±35.8%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
20250.070.000.17
20260.060.000.17
20270.060.000.17
20280.060.000.17
20290.060.000.17

Forster's Tern Survey Routes in South Dakota

Routes recording Forster's Tern in South Dakota.
White Lake420111967
Long Lake320171977
Lennox219811981
Fort Pierre219981986
Crow Creek220191969
Veblen220082008
Britton220222001
Gettysburg220131992
Howard119861986
Volga120241969
Roswell119891989
Lacreek119911991
Wilmot119871969
Forbes119791979
Lane 2120122012

Forster's Tern Population Trend in Other States

alabamacaliforniacoloradodelawarefloridageorgiaidahoillinoisindianaiowakansaslouisianamarylandmichiganminnesotamontananebraskanevadanew-jerseynew-yorknorth-carolinanorth-dakotaoregonsouth-carolinatexasutahvirginiawashingtonwisconsinwyoming

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