O'Brien Island is part of the Elephant Island group of the South Shetland Islands and lies several km southwest of Eadie Island (IBA ANT035) in Bransfield Strait. O'Brien Island is largely ice free with an ice-capped summit rising to over 250 m. The IBA qualifies on the basis of the concentration of seabirds present (in particular Chinstrap Penguin (Pygoscelis antarctica) and Southern Fulmar (Fulmarus glacialoides)) and comprises all of O'Brien Island.
There are no research stations in the vicinity of the site, with the nearest facility ~160 km to the southwest on King George Island.
Approximately 21 400 pairs of Chinstrap Penguin, ~7880 pairs of Southern Fulmar and ~780 pairs of Cape Petrel ( Daption capense ) were estimated as breeding on O'Brien Island in 1977 (Furse 1978). Information on other bird species in the area is not available.
Non-bird biodiversity: None known.
BirdLife International (2020) Important Bird Areas factsheet: O’Brien Island. Downloaded from http://www.birdlife.org on 21/10/2020.