ACAP Breeding Site No. 88. Penguin Island, South Shetland Islands supports Southern Giant Petrels

Penguin Island forms part of the South Shetland Islands lying off the Antarctic Peninsula. It lies close to the southern coast of King George Island in front of the side of King George Bay. It is an oval-shaped ice-free island 1.4 km wide and 1.7 km long. The island is an old volcano no longer active. Its cone is the 170-m high Deacon Peak, which slopes gently down to a landing beach.

Penguin Island seen from Turret Point on King George Island

A Chinstrap Penguin colony on Penguin Island

The Southern Giant Petrel Macronectes giganteus is the only ACAP-listed species breeding on Penguin Island. Breeding grounds are located on sloping terrain made up of lichens, mosses, vascular plants and scree among irregular formations of volcanic origin above low cliffs close to the sea. Most nests in small groups or singly are located in the north-east of the island, facing Turret Point (ALSA Breeding Site No. 89) on King George Island.

A Southern Giant Petrel colony on Penguin Island

A white-phase Southern Giant Petrel breeding on Penguin Island

A Southern Giant Petrel on its pebble nest on Penguin Island

A Southern Giant Petrel's nest of lava pebbles, shells and lichen on Penguin Island

 Population censuses of Southern Giant Petrels made by Brazilian researchers from the Universidade do Vale do Rio dos Sinos show inter-annual variation in breeding pair numbers, with only 138 pairs in 2011/12 (on 10 December) (another count is of 288 pairs recorded in 2012) and 418 pairs in the 2012/13 season (on 10 December).  Earlier censuses by the Antarctic Site Inventory from 1997/98 to 1999/2000 ranged from 439 to 634 occupied nests, suggesting a population decrease since then.

Tourist visits to the island are managed by a Visitor Site Guide document produced by the Antarctic Treaty System, which provides specific procedures for visitors to follow; three giant petrel breeding sites are closed to visitors with a 50-m precautionary distance.  Penguin Island was previously classified as an Important Bird Area by BirdLife International, but due to the decline in its Southern Giant Petrel population it no longer qualifies as one and so has been delisted.

Photographs by Maria Virginia Petry.

With thanks to Patricia Pereira Serafini .

Selected Literature:

Antarctic Treaty System 2014.  Penguin Island Antarctic Treaty Visitor Site Guide.  2 pp.

Harris, C.M., Lorenz, K., Fishpool, L.D.C., Lascelles, B., Cooper, J., Coria, N.R., Croxall, J.P., Emmerson, L.M., Fijn, R., Fraser, W.L., Jouventin, P., LaRue, M.A., Le Maho, Y., Lynch, H.J., Naveen, R., Patterson-Fraser, D.L., Peter, H.-U., Poncet, S., Phillips, R.A., Southwell, C.J., van Franeker, J.A., Weimerskirch, H., Wienecke, B. & Woehler, E.J. 2015. Important Bird Areas in Antarctica 2015.  Cambridge: BirdLife International and Environmental Research & Assessment Ltd.  302 pp.

Jablonski, B. 1984. Distribution and numbers of penguins in the region of King George Island (South Shetlands Islands) in the breeding season 1980/1981. Polish Polar Research 5: 17-30.

Naveen, R. 1997.  The Oceanites Site Guide to the Antarctic Peninsula.  Chevy Chase: Oceanites Inc.  129 pp.

Naveen, R. 2003. Compendium of Antarctic Peninsula Visitor Sites 2nd Edition.  A Report to the United States Environmental Protection Agency. Chevy Chase: Oceanites Inc.  381 pp.

Naveen, R., Forrest, S.C., Dagit, R.G., Blight, L.K., Trivelpiece, W.Z. & Trivelpiece, S.G. 2000.  Censuses of penguin, Blue-eyed Shag, and Southern Giant Petrel populations in the Antarctic Peninsula region, 1994-2000.  Polar Record 36: 323-334.

Patterson, D.L., Woehler, E.J., Croxall, J.P., Cooper, J., Poncet, S., Peter, H.-U., Hunter, S. & Fraser, M.W. 2008. Breeding distribution and population status of the Northern Giant Petrel Macronectes halli and Southern Giant Petrel M. giganteus. Marine Ornithology 36: 115-124 & appendices.

Poncet, S. & Poncet, J. 2007.  Southern Ocean Cruising Second Edition.  Cambridge: Environmental Research & Assessment.  160 pp.

Maria Virginia Petry & Júlia Victória Grohmann Finger, Laboratório de Ornitologia e Animais Marinhos, Universidade do Vale do Rio dos Sinos, São Leopoldo, Brazil, 08 June 2017