Species · Illinois · BBS 2025 Release · 1966–2024
Carolina Wren Population Trend in Illinois
Carolina Wren in Illinois has surged: up 196% on the route-weighted index since 1968.
+196%Since 1968
86Routes In State
58Years
Notable Carolina Wren Trends in Illinois
long arc increasecomputed index
Carolina Wren has surged in Illinois: up 196% on the route-weighted index since 1968.
Carolina Wren Population Forecast in Illinois
If the recent trend holds, Carolina Wren in Illinois is projected to fall about 15% by 2029 — from 5.1 in 2024 to a central estimate of 4.3 (95% range 2.0–6.6). A 5-year backtest shows a typical error of ±97.2%, with 60% of held-out values landing inside the 95% band.
-15%Change by 2029
4.3Projected 2029 index
2.0–6.695% range
±97.2%Backtest error
| Year | Projected index | 95% low | 95% high |
|---|---|---|---|
| 2025 | 4.1 | 1.8 | 6.4 |
| 2026 | 4.1 | 1.8 | 6.5 |
| 2027 | 4.2 | 1.9 | 6.5 |
| 2028 | 4.2 | 1.9 | 6.6 |
| 2029 | 4.3 | 2.0 | 6.6 |
Carolina Wren Survey Routes in Illinois
| Cave In Rock | 37 | 2024 | 1993 |
| Pulaski | 31 | 2024 | 1970 |
| Belknap | 25 | 2024 | 1970 |
| Royalton | 25 | 2024 | 2001 |
| Sandusky | 23 | 2023 | 1993 |
| Brownville | 22 | 2024 | 1993 |
| Belleview | 18 | 2024 | 1966 |
| Eldred | 17 | 2019 | 1993 |
| York | 15 | 2024 | 1993 |
| Bradbury | 14 | 2024 | 1970 |
| Mt Vernon | 14 | 2024 | 1971 |
| Karnak | 14 | 2024 | 2001 |
| Bremen | 13 | 2024 | 1969 |
| Mascoutah Lk | 12 | 2024 | 1969 |
| Brnt Prairie | 12 | 2024 | 1976 |
| St Morgan | 11 | 2022 | 1967 |
| Beaverdam Lk | 11 | 2023 | 1970 |
| Delwood | 10 | 2024 | 1971 |
| Grape Creek | 9 | 2024 | 2002 |
| Concord | 8 | 2024 | 1967 |
| Marshall | 8 | 2024 | 2003 |
| Athens | 8 | 2024 | 1995 |
| Darmstadt | 7 | 2024 | 1993 |
| Olney | 6 | 2024 | 1968 |
| Yale | 6 | 2024 | 1994 |
Carolina Wren Population Trend in Other States
Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.