Pedra Branca is the southernmost island in Australia, lying 26 km south of Whale Head in the Southwest National Park. The IBA also includes the nearby small Eddystone and Sidmouth Rocks. Pedra Branca is a rocky island with steep slopes on its eastern and western sides which rise to a north-south aligned central ridge. The key seabird species nest on tiered rock platforms and sparsely-vegetated cliff ledges of the island. Nest mounds of 270 pairs of Shy Albatross are interspersed with nests of Australasian Gannets, numbers of which have increased by approximately 7% per year from about 1000 pairs in 1978 to a congested 3317 pairs in 1995. Other seabirds are restricted to sites on unsuitable lower ledges that are affected by sea and weather conditions. Australasian Gannet numbers at nearby Eddystone Rock have also increased in recent decades from 20 pairs in 1947 to 189 pairs in 1998, when all suitable habitat was occupied.
Fairy Prion, Pacific Gull, Kelp Gull and Black-faced Cormorant breed in very small numbers. Silver Gull numbers increased from 10 pairs in 1978 to 52 pairs in 1990, with most nests located on rocks and overhangs where Pedra Branca Skinks are most abundant.
Non-bird biodiversity: Silver Gulls are believed to be responsible for declining numbers of the endemic Pedra Branca Skink, of which fewer than 400 individuals survive. Up to 500 Australian Fur Seals are regular and New Zealand Fur Seals visit occasionally. Sarcocornia quinqueflora, which is sparse and confined to rock cracks, is the only plant species recorded for the island.
Pressure/threats to key biodiversity
Maintain current protection protocols for seabird breeding colonies, under which unregulated visits are prohibited. Further measures to reduce by-catch of seabirds by long-line fisheries are needed to protect Shy Albatrosses at sea.
Conservation responses/actions for key biodiversity
Pedra Branca, Eddystone Rock and Sidmouth Rock are all included within the Tasmanian Wilderness World Heritage Area.
Part of Southwest National Park.
Land is owned by the Tasmanian State Government and managed by the Department of Primary Industries and Water.
BirdLife International (2019) Important Bird Areas factsheet: Pedra Branca. Downloaded from
http://www.birdlife.org on 14/12/2019.