The Twin Islets form a close pair of small, steep-sided,

granite Granite () is a coarse-grained (phaneritic) intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content of silica and alkali metal oxides that slowly cools and solidifies undergro ...

islands, with a combined area of 5.61 ha, in south-eastern

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

. They are part of

Tasmania ) , nickname = , image_map = Tasmania in Australia.svg , map_caption = Location of Tasmania in AustraliaCoordinates: , subdivision_type = Country , subdi ...

’s

Hogan Group The Hogan Group is a collection of six (to eight) islands and islets located in the Bass Strait that define part of the border between mainland Australia and the island state of Tasmania. Within the jurisdiction of Tasmania, the Hogan Group for ...

, lying in northern

Bass Strait Bass Strait () is a strait separating the island state of Tasmania from the Australian mainland (more specifically the coast of Victoria, with the exception of the land border across Boundary Islet). The strait provides the most direct waterwa ...

between the

Furneaux Group The Furneaux Group is a group of approximately 100 islands located at the eastern end of Bass Strait, between Victoria and Tasmania, Australia. The islands were named after British navigator Tobias Furneaux, who sighted the eastern side of th ...

and

Wilsons Promontory Wilsons Promontory, is a peninsula that forms the southernmost part of the Australian mainland, located in the state of Victoria. South Point at is the southernmost tip of Wilsons Promontory and hence of mainland Australia. Located at nearb ...

Victoria Victoria most commonly refers to: * Victoria (Australia), a state of the Commonwealth of Australia * Victoria, British Columbia, provincial capital of British Columbia, Canada * Victoria (mythology), Roman goddess of Victory * Victoria, Seychelle ...

Fauna

Recorded breeding

seabird Seabirds (also known as marine birds) are birds that are adapted to life within the marine environment. While seabirds vary greatly in lifestyle, behaviour and physiology, they often exhibit striking convergent evolution, as the same enviro ...

and

wader 245px, A flock of Dunlins and Red knots">Red_knot.html" ;"title="Dunlins and Red knot">Dunlins and Red knots Waders or shorebirds are birds of the order Charadriiformes commonly found wikt:wade#Etymology 1, wading along shorelines and mudflat ...

species include

little penguin The little penguin (''Eudyptula minor'') is a species of penguin from New Zealand. They are commonly known as little blue penguins or blue penguins owing to their slate-blue plumage and are also known by their Māori name . The Australian lit ...

short-tailed shearwater The short-tailed shearwater or slender-billed shearwater (''Ardenna tenuirostris''; formerly ''Puffinus tenuirostris''), also called yolla or moonbird, and commonly known as the muttonbird in Australia, is the most abundant seabird species in A ...

fairy prion The fairy prion (''Pachyptila turtur'') is a small seabird with the standard prion plumage of blue-grey upperparts with a prominent dark "M" marking and white underneath. The sexes are alike. This is a small prion of the low subantarctic and sub ...

common diving-petrel The common diving petrel (''Pelecanoides urinatrix''), also known as the smaller diving petrel or simply the diving petrel, is a diving petrel, one of four very similar auk-like small petrels of the southern oceans. It is native to South Atlanti ...

Pacific gull The Pacific gull (''Larus pacificus'') is a very large gull, native to the coasts of Australia. It is moderately common between Carnarvon in the west, and Sydney in the east, although it has become scarce in some parts of the south-east, as a re ...

and

sooty oystercatcher The sooty oystercatcher (''Haematopus fuliginosus'') is a species of oystercatcher. It is a wading bird endemic to Australia and commonly found on its coastline. It prefers rocky coastlines, but will occasionally live in estuaries. All of its fea ...

.Brothers, Nigel; Pemberton, David; Pryor, Helen; & Halley, Vanessa. (2001). ''Tasmania’s Offshore Islands: seabirds and other natural features''. Tasmanian Museum and Art Gallery: Hobart.

References

Hogan Group {{Tasmania-geo-stub