Current view: Text account
Site description (2015 baseline):
Site location and context
Holl Island and O'Connor Island are situated in the southwest Windmill Islands, Budd Coast, Wilkes Land. Holl Island is roughly triangular in shape and up to 3 km long. O'Connor Island is ~1.7 km long and up to 0.7 km wide and lies ~600 m to the east, separated by a narrow channel and Werlein Island. Both islands are of rocky and hilly topography and are ice free in summer. Holl Island rises to ~90 m, with steep cliffs along the northwestern coast, while O'Connor Island has a maximum elevation of ~80 m. Several small lakes are present on Holl Island.
The IBA qualifies on the basis of the Adélie Penguin (
Pygoscelis adeliae) colony present, and comprises Holl Island, O'Connor Island and the intervening islands and marine area.
The nearest permanent station is Casey (AUS), ~14 km to the north on Bailey Peninsula.
Woehler
et al. (1991) counted 11 875 breeding pairs of Adélie Penguin on Holl Island and 4748 pairs on O'Connor Island in 1989/90, and noted the colony has been increasing since counts were first made in 1961. This compares with ~30 514 breeding pairs (95% CI 18 443, 49 850) of Adélie Penguin on both Holl Island and O'Connor Island as estimated from January 2011 satellite imagery (Lynch & LaRue 2014). While this more recent count suggests almost a doubling of numbers over 21 years, it is not clear whether this apparent change relates to inter-seasonal fluctuations, methodological differences, or represents a real increase in the local Adélie Penguin population.
Approximately 1084 and 327 breeding pairs of Snow Petrel (
Pagodroma nivea) were estimated on Holl Island and O'Connor Island respectively in 2002/03 (Olivier, Lee & Woehler 2004). Although numbers are unknown, Cape Petrels (
Daption capense) (Murray & Luders 1990) and South Polar Skuas (
Catharacta maccormicki) also breed on both islands, with breeding Wilson's Storm-petrels (
Oceanites oceanicus) confirmed only on Holl Island (Woehler
et al. 1991; Australian Antarctic Data Centre 2012). Creuwels
et al. (2007) estimated 400 breeding pairs of Southern Fulmar (
Fulmarus glacialoides) present on Holl Island in 1977/78.
Non-bird biodiversity: Weddell (
Leptonychotes weddellii), Leopard (
Hydrurga leptonyx) and Southern Elephant (
Mirounga leonina) seals have been reported in the area (Murray & Luders 1990; Woehler
et al. 1991).
Pressure/threats to key biodiversity
None known.
Recommended citation
BirdLife International (2024) Important Bird Area factsheet: Holl Island / O’Connor Island (Antarctica). Downloaded from
https://datazone.birdlife.org/site/factsheet/holl-island--o’connor-island-iba-antarctica on 23/11/2024.
