Species · Delaware · BBS 2025 Release · 1966–2024
Kentucky Warbler Population Trend in Delaware
Kentucky Warbler in Delaware has collapsed: down 80% on the route-weighted index since 1968.
-80%Since 1968
15Routes In State
51Years
Notable Kentucky Warbler Trends in Delaware
long arc declinecomputed index
Kentucky Warbler has collapsed in Delaware: down 80% on the route-weighted index since 1968.
Kentucky Warbler Population Forecast in Delaware
If the recent trend holds, Kentucky Warbler in Delaware is projected to fall about 100% by 2027 — from 0.20 in 2022 to a central estimate of 0.00 (95% range 0.00–0.77). A 5-year backtest shows a typical error of ±174.8%, with 100% of held-out values landing inside the 95% band.
-100%Change by 2027
0.00Projected 2027 index
0.00–0.7795% range
±174.8%Backtest error
| Year | Projected index | 95% low | 95% high |
|---|---|---|---|
| 2023 | 0.00 | 0.00 | 0.77 |
| 2024 | 0.00 | 0.00 | 0.77 |
| 2025 | 0.00 | 0.00 | 0.77 |
| 2026 | 0.00 | 0.00 | 0.77 |
| 2027 | 0.00 | 0.00 | 0.77 |
Kentucky Warbler Survey Routes in Delaware
| Mt Pleasant | 1 | 2007 | 1966 |
| Wilmington | 1 | 2000 | 1967 |
| Harrington | 1 | 2021 | 1966 |
| Frederica | 1 | 2005 | 1966 |
| Dover | 1 | 1979 | 1979 |
| Frankford | 1 | 2008 | 1966 |
| Holleyville | 1 | 2003 | 1966 |
| Lowes Xrds | 1 | 1980 | 1966 |
| Bethany Bch | 1 | 1973 | 1966 |
| Milton | 1 | 2016 | 1966 |
| Blackbird | 1 | 2022 | 2019 |
| Holleyville 2 | 1 | 2007 | 2006 |
| Pepperbox | 1 | 2005 | 1998 |
| Georgetown | 1 | 2014 | 1992 |
| Pepperbox 2 | 1 | 2019 | 2017 |
Kentucky Warbler Population Trend in Other States
Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.