 The swamps are filled by two periodical high tides that occur during the full moon days of May and June.The swamp along with the sanctuary is the important wintering and staging area for waders and water birds.According to 2011 census, Vedaranyam had a population of 34,266 with a sex-ratio of 1,068 females for every 1,000 males, much above the national average of 929.