Penguin Island is an oval-shaped ice-free island ~1.6 km across lying ~1 km southeast of Turret Point on the southern coast of King George Island. The original IBA comprised all of Penguin Island.
Penguin Island is an extinct volcanic cone, which rises to ~170 m at Deacon Peak. The shoreline is generally of low cliffs, although a beach on the northern coast offers the most practical access. A small lake lies in the northeast of the island. Vegetation includes a variety of lichens, mosses, and the two vascular plant species Antarctic Hairgrass (Deschampsia antarctica) and Antarctic Pearlwort (Colobanthus quitensis) (ATS Visitor Site Guide, Penguin Island, accessed 06/08/2010).
The nearest permanent scientific station is Comandante Ferraz (Brazil) in Admiralty Bay ~25 km to the west, more information on which can be found under IBA ANT037.
The site originally qualified as an IBA because it supported a wide range of birds, including a substantial colony of Southern Giant Petrel (Macronectes giganteus) breeding along the northern and northwestern shoreline, with 634 pairs recorded in 1999 (Naveen 2003). Southern Giant Petrel numbers have fluctuated, although appear to have declined with 288 pairs recorded in 2012 (Antarctic Site Inventory (ASI) data; R. Naveen and H. Lynch pers. comm. 2014), on which basis the site no longer qualifies as an IBA.
Adélie Penguins (Pygoscelis adeliae) breed on the southern side of Penguin Island, with 2441 pairs recorded in 1997 (Naveen 2003). Approximately 7581 pairs of Chinstrap Penguin (Pygoscelis antarctica) were breeding on Penguin Island in 1980 (Jablonski 1984). ASI data reported that Adélie Penguins decreased to 54 breeding pairs in 2013, while Chinstraps decreased to 1545 (R. Naveen and H. Lynch pers. comm. 2014). The combined number of penguins present, and other seabirds, is no longer sufficient to qualify the site for IBA status.
Other confirmed breeders include the Antarctic Tern (Sterna vittata), Kelp Gull (Larus dominicanus) and skuas (Catharacta spp.). The Snowy Sheathbill (Chionis albus) and Wilson's Storm-petrel (Oceanites oceanicus) are frequent visitors and may breed at the site, whilst the Imperial Shag (Phalacrocorax [atriceps] bransfieldensis) is a regular visitor (ATS Visitor Site Guidelines, Penguin Island).
Non-bird biodiversity: Southern Elephant Seals (Mirounga leonina) and Weddell Seals (Leptonychotes weddellii) regularly haul out on Penguin Island (ATS Visitor Site Guidelines, Penguin Island, accessed 06/08/2010).
BirdLife International (2020) Important Bird Areas factsheet: Penguin Island, King George Island. Downloaded from http://www.birdlife.org on 14/08/2020.