Brown Bluff is a small ice-free section of the northern coastline on Tabarin Peninsula, approximately 13 km southeast of Hope Bay and 8 km west of Jonassen Island. A low-lying rock and ash beach rises steeply to reddish-brown north-facing cliffs of volcanic origin. The IBA qualifies on the basis of the large concentration of seabirds present (in particular Adélie Penguin (Pygoscelis adeliae)) and comprises the ice-free area of the bluff.
Erosion of the cliff face causes rock falls and slides along the shoreline, which may affect penguins nesting at the cliff-base. Naveen (2003) reports the lichens Xanthoria spp. and Caloplaca spp. growing on boulders at the shoreline and up to elevations of 185 m and mosses have been observed at higher altitudes.
The nearest permanent scientific stations are Esperanza (ARG) and Teniente de Navio Ruperto Elichiribehety (URY), situated 14 km to the northwest, more information on which can be found under IBA Hope Bay.
Approximately 20 000 pairs of Adélie Penguin nest in tightly packed groups on gentle slopes, terraces and ridges on and above the beach at Brown Bluff (Naveen & Lynch 2011). More recently, 18 630 breeding pairs were reported by the Antarctic Site Inventory in January 2013 (R. Naveen and H. Lynch pers. comm. 2014). Around 550 pairs of Gentoo Penguin (Pygoscelis papua) breed on flat terraces and low-lying slopes to the east of the Adélie Penguins (H. Lynch pers. comm. 2010). Kelp Gull (Larus dominicanus) nests are found throughout the site, whilst Wilson's Storm-petrels (Oceanites oceanicus) breed in rock crevices at higher altitudes. Other confirmed breeders include Cape Petrel (Daption capense), Snow Petrel (Pagodroma nivea), Imperial Shag (Phalacrocorax [atriceps] bransfieldensis), Snowy Sheathbill (Chionis albus), South Polar Skua (Catharacta maccormicki), Brown Skua (Catharacta antarctica) and Antarctic Tern (Sterna vittata) (Naveen & Lynch 2011).
Non-bird biodiversity: Weddell Seals (Leptonychotes weddellii) have been observed at Brown Bluff (ATS Visitor Site Guidelines, Brown Bluff).
BirdLife International (2019) Important Bird Areas factsheet: Brown Bluff. Downloaded from http://www.birdlife.org on 20/05/2019.