The Southern Indian Ocean Islands tundra is a

tundra In physical geography, tundra () is a type of biome where tree growth is hindered by frigid temperatures and short growing seasons. The term ''tundra'' comes through Russian (') from the Kildin Sámi word (') meaning "uplands", "treeless mou ...

ecoregion An ecoregion (ecological region) or ecozone (ecological zone) is an ecologically and geographically defined area that is smaller than a bioregion, which in turn is smaller than a biogeographic realm. Ecoregions cover relatively large areas of ...

that includes several

subantarctic The sub-Antarctic zone is a region in the Southern Hemisphere, located immediately north of the Antarctic region. This translates roughly to a latitude of between 46° and 60° south of the Equator. The subantarctic region includes many islands ...

islands in the southern

Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or ~19.8% of the water on Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia to the east. To the south it is bounded by t ...

Location and description

The ecoregion stretches from

Prince Edward Islands The Prince Edward Islands are two small uninhabited islands in the sub-Antarctic Indian Ocean that are part of South Africa. The islands are named Marion Island (named after Marc-Joseph Marion du Fresne, 1724–1772) and Prince Edward Island ...

in the west, past the Crozet Islands to the Kerguelen Islands 1500 km to the east, and includes the active volcano

Heard Island The Territory of Heard Island and McDonald Islands (HIMI) is an Australian external territory comprising a volcanic group of mostly barren Antarctic islands, about two-thirds of the way from Madagascar to Antarctica. The group's overall size ...

and the nearby

McDonald Islands The McDonald Islands () are an uninhabited archipelago in the southern Indian Ocean in the vicinity of Heard Island (). Together with Heard Island, they make up the Australian external Territory of Heard Island and McDonald Islands. The McDona ...

Flora

These rocky islands support a variety of plant life, such as

tussock grass Tussock grasses or bunch grasses are a group of grass species in the family Poaceae. They usually grow as singular plants in clumps, tufts, hummocks, or bunches, rather than forming a sod or lawn, in meadows, grasslands, and prairies. As perenni ...

es, that has adapted to the snowy and icy conditions. There are a number of endemic plant species including ''

Poa cookii ''Poa cookii'', sometimes called Cook's tussock-grass or bluegrass, is a species of tussock grass native to various subantarctic islands. The specific epithet honours British explorer James Cook who visited the Kerguelen Islands in 1776. Desc ...

'' grass and the Kerguelen cabbage ('' Pringlea antiscorbutica''), historically a source of

vitamin C Vitamin C (also known as ascorbic acid and ascorbate) is a water-soluble vitamin found in citrus and other fruits and vegetables, also sold as a dietary supplement and as a topical 'serum' ingredient to treat melasma (dark pigment spots) ...

for sailors, is found on all the islands, not only the Kerguelens. There are also a number of endemic lichens and liverworts.

Fauna

The islands are home to birds and insects such as butterflies,

moth Moths are a paraphyletic group of insects that includes all members of the order Lepidoptera that are not butterflies, with moths making up the vast majority of the order. There are thought to be approximately 160,000 species of moth, many of w ...

weevil Weevils are beetles belonging to the superfamily Curculionoidea, known for their elongated snouts. They are usually small, less than in length, and herbivorous. Approximately 97,000 species of weevils are known. They belong to several families, ...

s, and

spider Spiders ( order Araneae) are air-breathing arthropods that have eight legs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude silk. They are the largest order of arachnids and rank seventh in total species ...

s as well as wildlife typical of the southern oceans such as penguins,

seal Seal may refer to any of the following: Common uses * Pinniped, a diverse group of semi-aquatic marine mammals, many of which are commonly called seals, particularly: ** Earless seal, or "true seal" ** Fur seal * Seal (emblem), a device to imp ...

s and seabirds. This ecoregion is a melting pot where related Antarctic and subantarctic species and subspecies co-exist, for example the following can all be found here: the sooty albatrosses (''

Phoebetria fusca The sooty albatross, dark-mantled sooty albatross or dark-mantled albatross,BirdLife International (2008b) (''Phoebetria fusca''), is a species of bird in the albatross family. They breed on sub-Antarctic islands and range at sea across the ...

''), light-mantled albatross (''

Phoebetria palpebrata The light-mantled albatross (''Phoebetria palpebrata'') also known as the grey-mantled albatross or the light-mantled sooty albatross, is a small albatross in the genus ''Phoebetria'', which it shares with the sooty albatross. The light-mantled ...

)'', northern giant petrel (''

Macronectes halli The northern giant petrel (''Macronectes halli''), also known as Hall's giant petrel, is a large predatory seabird of the southern oceans. Its distribution overlaps broadly, but is slightly north of, the similar southern giant petrel (''Macrone ...

''), southern giant petrel (''

Macronectes giganteus The southern giant petrel (''Macronectes giganteus''), also known as the Antarctic giant petrel, giant fulmar, stinker, and stinkpot, is a large seabird of the southern oceans. Its distribution overlaps broadly with the similar northern giant pet ...

'')), Antarctic fur seal ('' Arctophoca gazella'') and subantarctic fur seal ('' Arctophoca tropicalis'') on Prince Edward, Crozet and Heard Islands. Vulnerable or endangered birds include three endemics, the duck, Eaton’s pintail ('' Anas eatoni''), the large wandering albatross ('' Diomedea exulans'') and Kerguelen tern ('' Sterna virgata'') as well as a number of albatrosses (the two sooty albatrosses, Indian yellow-nosed albatross ('' Thalassarche carteri'') (the smallest of the

mollymawk The mollymawks are a group of medium-sized albatrosses that form the genus ''Thalassarche''. The name has sometimes been used for the genus ''Phoebetria'' as well, but these are usually called sooty albatrosses. They are restricted to the Sout ...

albatrosses), the large gray-headed albatross (''

Thalassarche chrysostoma The grey-headed albatross (''Thalassarche chrysostoma'') also known as the gray-headed mollymawk, is a large seabird from the albatross family. It has a circumpolar distribution, nesting on isolated islands in the Southern Ocean and feeding at h ...

''), and black-browed albatross ('' Thalassarche melanophrys'')), three penguins (western rockhopper penguin ('' Eudyptes chrysocome''), macaroni penguin ('' Eudyptes chrysolophus'') and gentoo penguin (''

Pygoscelis papua The gentoo penguin ( ) (''Pygoscelis papua'') is a penguin species (or possibly a species complex) in the genus ''Pygoscelis'', most closely related to the Adélie penguin (''P. adeliae'') and the chinstrap penguin (''P. antarcticus''). The earl ...

'') (the one with the white stripe across its head)), and a number of petrels (the two giant petrels, grey petrel ('' Procellaria cinerea'') and white-chinned petrel ('' Procellaria aequinoctialis'')). Other breeding birds include the land-based

black-faced sheathbill The black-faced sheathbill (''Chionis minor''), also known as the lesser sheathbill or paddy bird, is one of only two species of sheathbills, aberrant shorebirds which are terrestrial scavengers of subantarctic islands. Description They are du ...

and many seabirds

brown skua The brown skua (''Stercorarius antarcticus''), also known as the Antarctic skua, subantarctic skua, southern great skua, southern skua, or hākoakoa (Māori), is a large seabird that breeds in the subantarctic and Antarctic zones and moves furthe ...

, kelp gull (''

Larus dominicanus The kelp gull (''Larus dominicanus''), also known as the Dominican gull, is a gull that breeds on coasts and islands through much of the Southern Hemisphere. The nominate ''L. d. dominicanus'' is the subspecies found around South America, par ...

''), fulmar prion ('' Pachyptila crassirostris''), Antarctic prion ('' Pachyptila desolata''), slender-billed prion ('' Pachyptila belcheri''), fairy prion ('' Pachyptila turtur''), Antarctic tern ('' Sterna vittata''), Cape petrel ('' Daption capense''), black-bellied storm petrel ('' Fregetta tropica''), grey-backed storm petrel ('' Garrodia nereis''), blue petrel ('' Halobaena caerulea''), Wilson’s storm-petrel ('' Oceanites oceanicus''), common diving petrel ('' Pelecanoides urinatrix''), South Georgian diving-petrel ('' Pelecanoides georgicus''),

great-winged petrel The great-winged petrel (''Pterodroma macroptera'') is a petrel. Taxonomy This species was formerly treated as containing two subspecies - ''P. m. macroptera'' and ''P. m. gouldi'', the latter of which is endemic to New Zealand. As of 2014, th ...

, white-headed petrel ('' Pterodroma lessonii'') and soft-plumaged petrel ('' Pterodroma mollis''). The largest seabird colonies are on the Prince Edward Islands, followed by the Crozet Islands which have breeding colonies of all six species of albatross as well as more than half the world's population of king penguins ('' Aptenodytes patagonicus''). All six Antarctic seals can be found here, the two fur seals,

leopard seal The leopard seal (''Hydrurga leptonyx''), also referred to as the sea leopard, is the second largest species of seal in the Antarctic (after the southern elephant seal). Its only natural predator is the orca. It feeds on a wide range of prey incl ...

(''Hydrurga leptonyx''),

Weddell seal The Weddell seal (''Leptonychotes weddellii'') is a relatively large and abundant true seal with a circumpolar distribution surrounding Antarctica. The Weddell seal was discovered and named in the 1820s during expeditions led by British seali ...

(''Leptonychotes weddellii''),

southern elephant seal The southern elephant seal (''Mirounga leonina'') is one of two species of elephant seals. It is the largest member of the clade Pinnipedia and the order Carnivora, as well as the largest extant marine mammal that is not a cetacean. It gets its ...

(''Mirounga leonina''), and

crabeater seal The crabeater seal (''Lobodon carcinophaga''), also known as the krill-eater seal, is a true seal with a circumpolar distribution around the coast of Antarctica. They are medium- to large-sized (over 2 m in length), relatively slender and pale-c ...

(''Lobodon carcinophagus'')). The fur seals and southern elephant seal breed in the region, and are increasing in numbers now that seal-hunting has stopped, while large numbers of leopard seals winter on the rocks of Heard Island. The colony of southern elephant seals on Heard Island and the Kerguelens is one of the three largest in the world.

Threats and preservation

These isolated islands are relatively unspoilt but their wildlife is not very varied and therefore can be quickly damaged by any human activity and particularly by

introduced species An introduced species, alien species, exotic species, adventive species, immigrant species, foreign species, non-indigenous species, or non-native species is a species living outside its native distributional range, but which has arrived ther ...

of both plants and animals. For example, introduced grasses have taken over areas of some islands, while alien animals including moths,

salmon Salmon () is the common name for several commercially important species of euryhaline ray-finned fish from the family Salmonidae, which are native to tributaries of the North Atlantic (genus ''Salmo'') and North Pacific (genus '' Oncorhy ...

, the

mallard duck The mallard () or wild duck (''Anas platyrhynchos'') is a dabbling duck that breeds throughout the temperate and subtropical Americas, Eurasia, and North Africa, and has been introduced species, introduced to New Zealand, Australia, Peru, Bra ...

, rabbits, reindeer, sheep and goats have damaged island ecosystems. Cats and mice are a particular problem as both prey on breeding seabird colonies. Another particular threat is the danger to diving seabirds caught by

long-line fishing Longline fishing, or longlining, is a commercial fishing angling technique that uses a long ''main line'' with baited hooks attached at intervals via short branch lines called ''snoods'' or ''gangions''.Dissostichus eleginoides The Patagonian toothfish (''Dissostichus eleginoides'') is a species of notothen found in cold waters () between depths of in the southern Atlantic, Pacific, and Indian Oceans and Southern Ocean on seamounts and continental shelves around mos ...

'') in the seas around the islands; gray-headed albatross and white-chinned petrel have been especially damaged by this industry as they habitually follow fishing boats.

References

External links