Zekiah Swamp IBA encompasses 5,572 ha of forests and wetlands along Zekiah Swamp Run, a 30-km network of braided streams in eastern Charles County. The site extends from Poplar Hill Rd just south of Cedarville State Forest to Maryland Route 234 just north of Allen?s Fresh Run. Major habitat types include deciduous floodplain forest, of considerable diversity, and upland oak-hickory forest, together accounting for 80% of the area, and a number of shrub and emergent herbaceous wetlands, with many standing dead trees, formed as a result of beaver activity. Scattered patches of loblolly-shortleaf-pine forest account for just less than 3% of the area. About 113 ha of the IBA are owned and managed by the Maryland DNR as the Zekiah Swamp Natural Environment Area, while the remaining lands are privately owned. The northern half of the site lies within the Zekiah Rural Legacy Area.
Data from Bird Blitz surveys in 2009 demonstrated that the wild floodplain forests of Zekiah Swamp support significant state-level breeding populations of four Audubon/American Bird Conservancy Watchlist (Category Yellow) species. A significant population of Red-headed Woodpecker, a species of global conservation concern, breeds in the numerous snag-filled patches of beaver-flooded swamp throughout the site. Also with significant populations are three Forest-Interior Dwelling Species (FIDS) of continental conservation concern: Prothonotary Warbler, Wood Thrush, and Kentucky Warbler. FIDS are birds which the Maryland Department of Natural Resources lists as requiring large areas of intact forest interior in order to breed successfully.