Species · Delaware · BBS 2025 Release · 1966–2024
Black-and-white Warbler Population Trend in Delaware
Black-and-white Warbler in Delaware has declined: down 44% on the route-weighted index since 1968.
-44%Since 1968
12Routes In State
33Years
Notable Black-and-white Warbler Trends in Delaware
No notable trend signals for Black-and-white Warbler in Delaware. See the full index history below.
Black-and-white Warbler Population Forecast in Delaware
If the recent trend holds, Black-and-white Warbler in Delaware is projected to fall about 89% by 2029 — from 0.20 in 2024 to a central estimate of 0.02 (95% range 0.00–0.76). A 5-year backtest shows a typical error of ±185.7%, with 80% of held-out values landing inside the 95% band.
-89%Change by 2029
0.02Projected 2029 index
0.00–0.7695% range
±185.7%Backtest error
| Year | Projected index | 95% low | 95% high |
|---|---|---|---|
| 2025 | 0.06 | 0.00 | 0.80 |
| 2026 | 0.05 | 0.00 | 0.79 |
| 2027 | 0.04 | 0.00 | 0.78 |
| 2028 | 0.03 | 0.00 | 0.77 |
| 2029 | 0.02 | 0.00 | 0.76 |
Black-and-white Warbler Survey Routes in Delaware
| Lowes Xrds | 2 | 1991 | 1966 |
| Bethany Bch | 2 | 1966 | 1966 |
| Millsboro | 2 | 2017 | 2017 |
| Pepperbox | 2 | 2016 | 1999 |
| Mt Pleasant | 1 | 1984 | 1966 |
| Harrington | 1 | 1968 | 1968 |
| Frederica | 1 | 2012 | 1966 |
| Frankford | 1 | 1993 | 1966 |
| Holleyville | 1 | 2003 | 1966 |
| Milton | 1 | 1975 | 1970 |
| Georgetown | 1 | 1997 | 1992 |
| Pepperbox 2 | 1 | 2024 | 2022 |
Black-and-white Warbler Population Trend in Other States
alabamaarkansascaliforniaconnecticutgeorgiaillinoisindianakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourinebraskanew-hampshirenew-jerseynew-yorknorth-carolinanorth-dakotaohiooklahomapennsylvaniarhode-islandsouth-carolinatennesseetexasvermontvirginiawest-virginiawisconsinwyoming
Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.