Cape Adare is situated at the north of the Adare Peninsula, on the Borchgrevink Coast, northern Victoria Land. Ridley Beach lies ~1.6 km southwest of Cape Adare, and is a roughly triangular pebbly depositional feature beneath the steep slopes of the Cape Adare promontory which rises up ~300 m (Reid 1962). Huts and other historic relics left by the Borchgrevink (1898-1900) and Scott Terra Nova (1910-13) expeditions are present at the site, and these are protected under ASPA No. 159 Cape Adare, Borchgrevink Coast.
The IBA qualifies on the basis of the large Adélie Penguin (Pygoscelis adeliae) and South Polar Skua (Catharacta maccormicki) colonies present, and comprises ice free ground at Ridley Beach. The IBA encompasses ASPA No. 159, although the protection relates to the historic values of the site rather than resident birdlife.
The nearest permanent stations are Mario Zucchelli (ITA) and Jang Bogo (KOR), ~420 km south in Terra Nova Bay.
Historically, Cape Adare has been the largest Adélie Penguin colony in the Ross Sea, although recent counts at Cape Crozier have rivalled those at Cape Adare (Lyver et al. 2014). The Adélie colony at Cape Adare had a mean count of 227 000 breeding pairs over 4 seasons sampled between 1981 and 2012 (Lyver et al. 2014). The colony occupies Ridley Beach, extending to include a talus slope forming a ledge ~10 m above the beach and part of the western slopes of the Cape Adare promontory. A South Polar Skua colony of ~300 pairs breeds above the penguin colony at the crest of the promontory (Reid 1962), with 306 pairs estimated from a ground count made in January 1982 (Ainley et al. 1986). Confirmed visitors to the area are Southern Giant Petrel (Macronectes giganteus), Antarctic Petrel (Thalassoica antarctica), Snow Petrel (Pagodroma nivea) and Wilson's Storm-petrel (Oceanites oceanicus), although these species are not known to breed in the area.
Non-bird biodiversity: Weddell Seals (Leptonychotes weddellii) are reported to haul out on Ridley Beach.
BirdLife International (2020) Important Bird Areas factsheet: Cape Adare. Downloaded from http://www.birdlife.org on 03/12/2020.