Species · Delaware · BBS 2025 Release · 1966–2024
Chimney Swift Population Trend in Delaware
Chimney Swift in Delaware has declined: down 41% on the route-weighted index since 1968.
-41%Since 1968
17Routes In State
58Years
Notable Chimney Swift Trends in Delaware
No notable trend signals for Chimney Swift in Delaware. See the full index history below.
Chimney Swift Population Forecast in Delaware
If the recent trend holds, Chimney Swift in Delaware is projected to rise about 35% by 2029 — from 4.8 in 2024 to a central estimate of 6.5 (95% range 1.1–12). A 5-year backtest shows a typical error of ±67.3%, with 100% of held-out values landing inside the 95% band.
+35%Change by 2029
6.5Projected 2029 index
1.1–1295% range
±67.3%Backtest error
| Year | Projected index | 95% low | 95% high |
|---|---|---|---|
| 2025 | 6.7 | 1.4 | 12 |
| 2026 | 6.6 | 1.3 | 12 |
| 2027 | 6.6 | 1.2 | 12 |
| 2028 | 6.5 | 1.2 | 12 |
| 2029 | 6.5 | 1.1 | 12 |
Chimney Swift Survey Routes in Delaware
| Dover | 23 | 1987 | 1966 |
| Lowes Xrds | 20 | 1991 | 1966 |
| Harrington | 16 | 2024 | 1966 |
| Milton | 12 | 2016 | 1966 |
| Milton 2 | 8 | 2017 | 2017 |
| Wilmington | 7 | 2014 | 1966 |
| Bethany Bch | 7 | 1990 | 1966 |
| Holleyville | 6 | 2004 | 1966 |
| Frederica | 5 | 2014 | 1966 |
| Mt Pleasant | 4 | 2019 | 1966 |
| Holleyville 2 | 4 | 2024 | 2006 |
| Georgetown | 4 | 2018 | 1992 |
| Frankford | 3 | 2012 | 1966 |
| Pepperbox | 3 | 2016 | 1998 |
| Pepperbox 2 | 3 | 2024 | 2017 |
| Blackbird | 1 | 2024 | 1994 |
| Millsboro | 1 | 2019 | 2017 |
Chimney Swift Population Trend in Other States
alabamaarkansascoloradoconnecticutfloridageorgiaillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanew-hampshirenew-jerseynew-yorknorth-carolinanorth-dakotaohiooklahomapennsylvaniarhode-islandsouth-carolinasouth-dakotatennesseetexasvermontvirginiawest-virginiawisconsinwyoming
Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.