The birds along twenty 500 m lengths of coastal borrowdyke (water-filled ditches left when clay is extracted to make a sea wall) in eastern England were counted in spring 2004 and occurrence related to features of habitat. A total of 45 species was recorded with species richness ranging from 5–21. The most widespread species were little grebe Tachybaptus ruficollis, mute swan Cygnus olor, mallard Anas platyrhynchos, moorhen Gallinula chloropus, coot Fulica atra, sedge warbler Acrocephalus schoenobaenus, reed warbler Acrocephalus scirpaceus and reed bunting Emberiza schoeniclus, all typical wetland birds. Of 20 habitat variables measured, six (open water, narrow and broad marginal Scirpus, width, and low and tall thick scrub) were significant in describing species abundance data in a Canoco analysis. The linear coastal habitat of borrowdykes is regionally important for the conservation of some wetland species and current rotational management for land drainage purposes maintains the variety of habitats to retain a diversity of bird species.