Species · Illinois · BBS 2025 Release · 1966–2024

Yellow-billed Cuckoo Population Trend in Illinois

Yellow-billed Cuckoo in Illinois has declined: down 29% on the route-weighted index since 1968.

-29%Since 1968
100Routes In State
58Years

Notable Yellow-billed Cuckoo Trends in Illinois

No notable trend signals for Yellow-billed Cuckoo in Illinois. See the full index history below.

Yellow-billed Cuckoo Population Forecast in Illinois

If the recent trend holds, Yellow-billed Cuckoo in Illinois is projected to fall about 43% by 2029 — from 2.5 in 2024 to a central estimate of 1.4 (95% range 0.00–3.8). A 5-year backtest shows a typical error of ±25.1%, with 100% of held-out values landing inside the 95% band.

-43%Change by 2029
1.4Projected 2029 index
0.003.895% range
±25.1%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
20251.70.004.0
20261.60.004.0
20271.50.003.9
20281.50.003.8
20291.40.003.8

Yellow-billed Cuckoo Survey Routes in Illinois

Routes recording Yellow-billed Cuckoo in Illinois.
Belknap2120241970
Belleview2020241966
Pulaski1520241970
Mascoutah Lk1420241967
Delwood1120241970
Royalton1020242001
Beaverdam Lk920231970
Cave In Rock820241993
Duncan Mills720241993
Eldred720211993
Eubanks720242002
Mt Vernon620241971
York620241993
Sandusky620231993
Karnak620242001
Putnam520221967
Bluff Spgs520241967
Bremen520241969
Yale520241993
Bradbury420241970
St Morgan420221967
Lake Summerset420192003
Clayton420212001
Kell420242001
Sheffield320221966

Yellow-billed Cuckoo Population Trend in Other States

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