Guild · Illinois · BBS 2025 Release · 1966–2024
Aerial Insectivores In Illinois
17 species in this guild. As a group they are +24% since 1968.
Guild Signals
No notable trend signals for aerial insectivores in Illinois. See the full index history below.
Forecast
If the recent trend holds, Aerial insectivores in Illinois is projected to fall about 19% by 2029 — from 5.7 in 2024 to a central estimate of 4.6 (95% range 3.7–5.5). A 5-year backtest shows a typical error of ±14%, with 80% of held-out values landing inside the 95% band.
-19%Change by 2029
4.6Projected 2029 index
3.7–5.595% range
±14%Backtest error
| Year | Projected index | 95% low | 95% high |
|---|---|---|---|
| 2025 | 4.6 | 3.7 | 5.5 |
| 2026 | 4.6 | 3.7 | 5.5 |
| 2027 | 4.6 | 3.7 | 5.5 |
| 2028 | 4.6 | 3.7 | 5.5 |
| 2029 | 4.6 | 3.7 | 5.5 |
Member Species In Illinois
| Bank Swallow | Hirundinidae | -95% |
| Least Flycatcher | Tyrannidae | -82% |
| Chuck-will's-widow | Caprimulgidae | -77% |
| Eastern Whip-poor-will | Caprimulgidae | -68% |
| Chimney Swift | Apodidae | -66% |
| Purple Martin | Hirundinidae | -44% |
| Common Nighthawk | Caprimulgidae | -27% |
| Eastern Kingbird | Tyrannidae | -8% |
| Willow Flycatcher | Tyrannidae | +5% |
| Barn Swallow | Hirundinidae | +10% |
| Great Crested Flycatcher | Tyrannidae | +122% |
| Tree Swallow | Hirundinidae | +140% |
| Eastern Wood-Pewee | Tyrannidae | +203% |
| Eastern Phoebe | Tyrannidae | +378% |
| Acadian Flycatcher | Tyrannidae | +447% |
| Northern Rough-winged Swallow | Hirundinidae | +458% |
| Cliff Swallow | Hirundinidae | 179× |
Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.