They are part of the Betsey Island Group, lying close to the south-eastern coast of Tasmania around the entrance to the River Derwent.

It is classified as an Important Bird Area by BirdLife International; it is an important site for little penguins with an estimated 15,000 pairs breeding there,[1] short-tailed shearwaters (130,000-170,000 nesting burrows), and black-faced cormorants (over 200 breeding pairs).

(Cassell's Picturesque Australasia (1889): page 142)[6] The northern part of the island is dominated by Tasmanian blue gum forest, with the southern part mainly sedgeland.

Problem weeds are Cape Leeuwin wattle and boxthorn.

Apart from the penguins, shearwaters and cormorants, kelp gulls and white-bellied sea-eagles have nested there.