Falkland Islands - Biodiversity

Biodiversity

Biogeographically, the Falkland Islands are classified as part of the Antarctic ecozone and Antarctic Floristic Kingdom. Strong connections exist with the flora and fauna of Patagonia in South America. The only terrestrial mammal upon the arrival of Europeans was the warrah, a kind of fox found on both major islands. It became extinct in the mid 19th century. 14 species of marine mammals frequent the surrounding waters. The elephant seal, the fur seal, and the sea lions all breed on the islands, and the largest elephant seal breeding site has over 500 animals in it. 227 bird species have been seen on the islands, over 60 of which are known to breed on the islands. There are two endemic species of bird, and 14 endemic subspecies. There are five penguin species breeding on the islands, and over 60% of the global black-browed albatross population also breed in the area.

There are no native reptiles or amphibians on the islands. Over 200 species of insects have been recorded, along with 43 spider species and 12 worm species. Only 13 terrestrial invertebrates are recognised as endemic, although information on many species is lacking and it is suspected up to two thirds of species found are actually endemic. Due to the island environment, many insect species have developed reduced or absent wings. There are around 129 freshwater invertebrates, the majority being rotifer; however, the identification of some species remains in dispute. Six species of fish are found in freshwater areas, including zebra trout (aplochiton zebra) and falklands minnows (Galaxias maculatus). Different species of krill are found in Falkland waters, with lobster krill inhabiting the warmer waters in the north.

There are no native tree species on the archipelago, although two species of bushes, fachine (Chiliotrichum diffusum) and native box are found. Other vegetation consists of grasses and ferns. Around 363 species of vascular plants, 21 species of ferns and clubmosses and 278 species of flowering plants have been recorded on the islands. Of the vascular plants, 171 are believed to be native and 13 to be endemic. Some bogs and fens exist and support some freshwater plant species, but these are not common on the islands. Tussac grass, which averages 6.6 ft (2 m) in height but can reach up to 13 ft (4 m), is found within 300 m (1,000 ft) of the coast where it forms bands around larger islands. The dense canopies formed create an insulated micro-climate suitable for many birds and invertebrates. The Pale Maiden (Sisyrinchium jubatum) is the islands' national flower.

There is little long-term data on habitat changes, so the extent of human impact is unclear. Vegetation such as tussac grass, fachine, and native box have been heavily impacted by introduced grazing animals. Many breeding birds similarly only live on offshore islands, where introduced animals such as cats and rats are not found. Virtually the entire area of the islands is used as pasture for sheep. There is also an introduced reindeer population, which was brought to the islands in 2001 for commercial purposes. Rats and Grey foxes have been introduced and are having a detrimental impact on birds that nest on the shores, as are feral cats. 22 introduced plant species are thought to provide a significant threat to local flora.