BirdAnalyst
Species · Illinois · BBS 2025 Release · 1966–2024

Purple Martin Population Trend in Illinois

All statesAerial insectivores

Purple Martin in Illinois has declined: down 44% on the route-weighted index since 1968.

-44%Since 1968
100Routes In State
58Years

Notable Purple Martin Trends in Illinois

No notable trend signals for Purple Martin in Illinois. See the full index history below.

Purple Martin Population Forecast in Illinois

If the recent trend holds, Purple Martin in Illinois is projected to fall about 66% by 2029 — from 5.9 in 2024 to a central estimate of 2.0 (95% range 0.00–5.0). A 5-year backtest shows a typical error of ±54.7%, with 60% of held-out values landing inside the 95% band.

-66%Change by 2029
2.0Projected 2029 index
0.00–5.095% range
±54.7%Backtest error
19662029
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
20252.20.005.2
20262.20.005.1
20272.10.005.1
20282.10.005.0
20292.00.005.0

Purple Martin Survey Routes in Illinois

Routes recording Purple Martin in Illinois.
Seneca2620242009
Belknap2020241970
Bradbury1920241970
Humboldt1920241972
Mascoutah Lk1920241967
Bremen1920241969
Pawnee1820241967
Robinson1820231970
York1820241993
Athensville1720241971
Eubanks1720242001
Birds1520241976
Sherburnvill1420231967
Belleview1420241966
Janesville1420241976
Camp Point1420241994
Sheffield1220241966
Le Roy1220241993
Clayton1220242001
Chandlervill1120181971
Duncan Mills1120241997
Dudleyville1120242005
Martinsville1020241970
Terre Haute920241966
Sandusky820231993

Purple Martin Population Trend in Other States

alabamaarizonaarkansascaliforniacoloradoconnecticutdelawarefloridageorgiaindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

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