Due to the oceanic location of the Maldives its birds are mainly restricted to pelagic birds. Most of the species are similar to Eurasian migratory birds, and very few can be associated with the Indian sub-continent. Some of the birds are seasonal, such as the frigatebirds. There are also birds that dwell in marshes and island bush, like the grey heron and the moorhen. White terns are found occasionally on the southern islands.