Species · Illinois · BBS 2025 Release · 1966–2024
Cerulean Warbler Population Trend in Illinois
Cerulean Warbler in Illinois has declined: down 41% on the route-weighted index since 1973.
-41%Since 1973
13Routes In State
16Years
Notable Cerulean Warbler Trends in Illinois
No notable trend signals for Cerulean Warbler in Illinois. See the full index history below.
Cerulean Warbler Survey Routes in Illinois
| Athensville | 1 | 1973 | 1973 |
| Belleview | 1 | 2023 | 1969 |
| York | 1 | 2023 | 2023 |
| Sandusky | 1 | 2021 | 2021 |
| Cave In Rock | 1 | 2009 | 2009 |
| Mascoutah Lk | 1 | 1991 | 1988 |
| St Morgan | 1 | 2021 | 2021 |
| Olney | 1 | 1984 | 1969 |
| Flora | 1 | 1979 | 1979 |
| Birds | 1 | 2024 | 2023 |
| Bremen | 1 | 1986 | 1972 |
| Delwood | 1 | 1986 | 1986 |
| Beaverdam Lk | 1 | 1977 | 1977 |
Cerulean Warbler Population Trend in Other States
Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.