IBA Trigger species: Stewart Island Shag, Black-billed Gull, Black-fronted Tern, NZ Dotterel, Australasian Bittern
Besides the trigger species the following species are confirmed or likely to be breeding: Sooty Shearwater, Spotted Shag, Black Shag, Pied Shag, Little Shag, Spotted Shag, White-faced Heron, White Heron, Royal Spoonbill, Paradise Shelduck, Grey Teal, NZ Shoveler, NZ Scaup, Southern Black-backed Gull, Red-billed Gull, Caspian Tern, White-fronted Tern, Australasian Harrier, Pukeko, Marsh Crake, South Island Oystercatcher, Variable Oystercatcher, Pied Stilt, Banded Dotterel, South Island Fernbird, NZ Kingfisher, Welcome Swallow, NZ Pipit, Grey Warbler, South Island Fantail, Silvereye, Bellbird, Mallard, Rock Pigeon, Skylark, Hedge Sparrow, Blackbird, Song Thrush, Yellowhammer, Chaffinch, Greenfinch, Goldfinch, Redpoll, House Sparrow, Starling, Australian Magpie.
Other species recorded: Cattle Egret, Glossy Ibis, Pacific Golden Plover, Turnstone, Red (Lesser) Knot, Sharp-tailed Sandpiper, Pectoral Sandpiper.
BirdLife International (2019) Important Bird Areas factsheet: Omaui Island Oreti Estuary. Downloaded from http://www.birdlife.org on 14/11/2019.