Falklands Conservation

Update on Outer and Double Islands

Outer and Double Islands were purchased as nature reserves by Falklands Conservation in early 1998, largely with donations from members. On 30th October 1998 they were visited by Michael Morrison and Robin Woods as part of the second season's work on the Johnny Rook Survey. Robin Woods reports here on what they found.

April 1999

Double Island, with an approximate area of 9ha is in the eastern margin of Queen Charlotte Bay. It consists of two large hummocks, fairly densely covered in tussac grass up to a height of at least 2m, which are joined by a low sandy ridge. Ten sea lions were seen including one bull on the sand beach area. Twenty three bird species were recorded, of which 13 were probably breeding. These included Ruddy-headed Goose, Falkland Steamer Duck, Magellanic Penguin, Kelp Goose, Magellanic Oystercatcher, Blackish Oystercatcher, and Dark-faced Ground-tyrant. A flock of about 100 South American terns were observed fishing along an offshore reef, and some 70 Dolphin Gulls on the sandy beach where we found the wing of a Thin-billed Prion. A Johnny Rook, a second year bird, was present and it followed us to Outer Island.

Outer Island lies only 250m to the west of the westward-projecting reef of Double Island. It covers approximately 20ha and carried some taller and more dense tussac than Double Island. The tussac in the centre of the Island had been flattened and well-used by sea lions in many places, though only four young ones were seen on the eastern shore. An ancient cow's skull was found suggesting former usage for fattening beef (a common use of tussac islands in the past). Twenty four bird species were recorded here. In addition to those on Double Island, a single Gentoo Penguin was seen preening on the beach rocks, a colony of about 200 pairs of Rock Shags were discovered on the north-western cliffs, a Crested Caracara was heard calling at the southern point, and a Falkland Thrush singing on the east-facing slope.

These two Islands carry good stands of mature and in places, very dense tussac grass. Sea lions use both Islands, with apparently far more on Outer Island. Outer Island had a larger and less disturbed flora than Double Island. The endemic Falkland Cudweed was found growing here and ten of the 16 species identified were native plants. The extreme shortage of songbirds however, with no Black-throated Finches, Cobb's Wrens, Long-tailed Meadowlarks or Tussacbirds on either island was most noticeable. Unfortunately, both islands are heavily infested with rats. Many droppings were found beneath overhanging tussac skirts. The remains of a dead rat are now at the Natural History Museum, Tring, awaiting identification. Whilst Falklands Conservation as owners can protect these Islands from grazing by herbivores, their conservation status would be greatly enhanced if the rats could be eradicated. How we can undertake a project to do this is now being investigated.

Falklands Conservation UK Charity 1073859
Patron: HRH The Duke of York CVO ADC
Member of the International Union for Conservation of Nature | BirdLife International Representative