Abstract: nests, in which 100 nests filled with eggs, of common tern(Sterna hirund), little tern (S.albifrons), kentish plover(Charadrius alexamdrinus) and redshank (Tringa totanus) were found in the breeding colony of saunder's gull(Larus Saundersi) when the special survey of saunder's gull was proceeding in June of 1998 around the coast of Yancheng, Jiangsu Province. It was estimated that there were about 1,633 pairs of common tern, 414 of little tern, 146 of kentish plover and 139 of redshank in the breeding colony of saunder's gull based on the egg-filled nest density of them and the colonial area of saunder's gull.

Key words: Waterbirds, Nest density, Number of adults, Yancheng, Jiangsu Province.