Pedra Branca is a rock islet in the Southern Ocean, off the southern coast of Tasmania, Australia. The island is situated approximately 26 km (16 mi) south southeast of South East Cape and is contained within the Southwest National Park, part of the Tasmanian Wilderness World Heritage Site. An erosional remnant of the Tasmanian mainland, the island is approximately 270 m (890 ft) long, 100 m (330 ft) wide, with an elevation of 60 m (200 ft) above sea level. The island is estimated to have separated from the Tasmanian mainland at least 15,000 years ago.

The Australasian gannet, also known as the Australian gannet or tākapu, is a large seabird of the booby and gannet family, Sulidae. Adults are mostly white, with black flight feathers at the wingtips and lining the trailing edge of the wing. The central tail feathers are also black. The head is tinged buff-yellow, with a pearly grey bill edged in dark grey or black, and blue-rimmed eyes. Young birds have mottled plumage in their first year, dark above and light below. The head is an intermediate mottled grey, with a dark bill. The birds gradually acquire more white in subsequent seasons until they reach maturity after five years.