The Port Davey IBA consists of selected islands in the Breaksea Island, Swainson Island, Mutton Bird Island and Trumpeter Islets Groups off the south-west coast of Tasmania. These four island groups collectively comprise a string of small inshore islands of Southwest National Park, extending from Hobbs Island, about 10 km north of Port Davey, to Mutton Bird Island, about 10 km south of Port Davey. The IBA includes the following islands which are important for breeding seabirds: Breaksea Islands, Kathleen Island and Mavourneen Rocks in the Breaksea Island Group; Big Caroline Rock, Swainson Island, Hay Island, Shanks Islands and Lourah Island in the Swainson Island Group; South East Mutton Bird Islet, South West Mutton Bird Islet, Mutton Bird Island, Sugarmouse Island, East Pyramids, Sugarloaf Rock, Wendar Island and Wild Wind Islets in the Mutton Bird Island Group; and The Coffee Pot, West Pyramid, Trumpeter Islets and Hobbs Island in the Trumpeter Islets Group. With the exception of Lourah Island, all islands captured by the IBA are small and rocky with sparse grass and annual herb cover, and sometimes with low shrubs on larger or sheltered islands. The western coast of Lourah Island is mostly devoid of vegetation, but the eastern shore has dense vegetation typical of the nearby mainland.
Pacific Gull and Sooty Oystercatcher also breed on islands around Port Davey; Brothers et al. (2001) recorded a total of 18 pairs and three nests of Pacific Gull and 33 pairs and one nest of Sooty Oystercatcher across the islands captured by this IBA.
Pressure/threats to key biodiversity
Investigate presence of invasive alien species, especially rats and cats. Monitor sample numbers and breeding success of seabirds.
All islands are contained within Southwest National Park.