Bleaker Island and its outlying islands, off the southeastern coast of East Falkland, are low lying and rarely exceed 15 m except at Semaphore Hill north-east of the settlement. Coasts vary from low cliffs with sloping bedrock beaches to wide sandy bays and sheltered coves. Inland, Bleaker Island is mostly open heathland, with several ponds, some of which provide good habitats for waterfowl. There are extensive coastal beds of giant kelp. Ghost Island lies only 300 m from Bleaker Island, across a channel thick with kelp and it is not known if rats are present. It is likely that this island, with two-thirds of its area covered with tall Tussac, has not been grazed. Sandy Bay Island has not been stocked but the rodent status is unclear. The island lies 1 mile (1.5 km) off the Bleaker coast and is relatively high, at nearly 20 m in the centre, with a good coverage of Tussac grass. The greater distance from Bleaker Island makes infestation by rats across the channel unlikely, though possible. Halt Island lies at the mouth of Bleaker Island harbour, only 1.3 miles (2 km) from the settlement, making this an obvious choice for stocking and grazing in the past. Again, the rodent status is not known. Few details exist for the smaller Tussac-covered First, Second and Third Islands in the settlement bay, except that First Island is linked to Bleaker and it is possible to cross on foot at low tides. In November 2003 the resident manager reported that all three islands had rats.
During a four-day surveying visit by a British Schools Exploring Society (BSES) party in November 2003, 46 possible breeding species were recorded, of which 37 were either confirmed or probably breeding. Afew immature Striated Caracaras visit the settlement but they are not known to breed within the group. The island rates A4i status through the large colonies of Imperial Shags and Rock Shags present in November 2003. The globally threatened Macaroni Penguin may breed, but this needs confirmation. The Tussacbird was numerous prior to rat infestation but very few are breeding now. Endemic sub-species present include Whitetufted/ Rolland’s Grebes, Black-crowned Night-herons and Upland Geese. The Falkland Grass Wren was present only in protected Tussac paddocks along the south-east-facing coast.
Non-bird biodiversity: The BSES recorded 79 species of flowering plants from 20 1-km squares; 53 were native, 26 were introduced species and four endemic: Lady’s Slipper Calceolari fothergillii, Clubmoss Cudweed Chevreulia lycopodioides, Vanilla Daisy Leucheria suaveolens and Coastal Nassauvia Nassauvia gaudichaudii. Interesting species of note included the Yellow Orchid Gavilea littoralis, Whitlowgrass Draba funiculosa, Californian Club-rush Schoenoplectus californicus and Gillie’s Dandelion Taraxacum gilliesii.
BirdLife International (2021) Important Bird Areas factsheet: Bleaker Island Group. Downloaded from http://www.birdlife.org on 13/04/2021.