The Southern Indian Ocean Islands tundra is a

tundra In physical geography, a tundra () is a type of biome where tree growth is hindered by frigid temperatures and short growing seasons. There are three regions and associated types of tundra: #Arctic, Arctic, Alpine tundra, Alpine, and #Antarctic ...

ecoregion An ecoregion (ecological region) is an ecological and geographic area that exists on multiple different levels, defined by type, quality, and quantity of environmental resources. Ecoregions cover relatively large areas of land or water, and c ...

that includes several

subantarctic The sub-Antarctic zone is a physiographic region in the Southern Hemisphere, located immediately north of the Antarctic region. This translates roughly to a latitude of between 46th parallel south, 46° and 60th parallel south, 60° south of t ...

islands in the southern

Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or approximately 20% of the water area of Earth#Surface, Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia (continent), ...

Location and description

The ecoregion stretches from

Prince Edward Islands The Prince Edward Islands are two small uninhabited subantarctic volcanic islands in the southern Indian Ocean that are administered by South Africa. They are named Marion Island (named after Marc-Joseph Marion du Fresne, 1724–1772) and P ...

in the west, past the

Crozet Islands The Crozet Islands (; or, officially, ''Archipel Crozet'') are a sub-Antarctic archipelago of small islands in the southern Indian Ocean. They form one of the five administrative districts of the French Southern and Antarctic Lands. History ...

to the

Kerguelen Islands The Kerguelen Islands ( or ; in French commonly ' but officially ', ), also known as the Desolation Islands (' in French), are a group of islands in the subantarctic, sub-Antarctic region. They are among the Extremes on Earth#Remoteness, most i ...

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 land ...

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 ...

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 perennia ...

es, that has adapted to the snowy and icy conditions. There are a number of endemic plant species including '' Poa cookii'' 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, berries and vegetables. It is also a generic prescription medication and in some countries is sold as a non-prescription di ...

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

lichen A lichen ( , ) is a hybrid colony (biology), colony of algae or cyanobacteria living symbiotically among hypha, filaments of multiple fungus species, along with yeasts and bacteria embedded in the cortex or "skin", in a mutualism (biology), m ...

s and

liverworts Liverworts are a group of non-vascular plant, non-vascular embryophyte, land plants forming the division Marchantiophyta (). They may also be referred to as hepatics. Like mosses and hornworts, they have a gametophyte-dominant life cycle, in wh ...

Fauna

The islands are home to birds and insects such as

butterflies Butterflies are winged insects from the lepidopteran superfamily Papilionoidea, characterized by large, often brightly coloured wings that often fold together when at rest, and a conspicuous, fluttering flight. The oldest butterfly fossi ...

moth Moths are a group of insects that includes all members of the order Lepidoptera that are not Butterfly, butterflies. They were previously classified as suborder Heterocera, but the group is Paraphyly, paraphyletic with respect to butterflies (s ...

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 fa ...

s, and

spider Spiders (order (biology), order Araneae) are air-breathing arthropods that have eight limbs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude spider silk, silk. They are the largest order of arachnids and ran ...

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

penguin Penguins are a group of aquatic flightless birds from the family Spheniscidae () of the order Sphenisciformes (). They live almost exclusively in the Southern Hemisphere. Only one species, the Galápagos penguin, is equatorial, with a sm ...

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, also called "true seal" ** Fur seal ** Eared seal * Seal ( ...

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 (''Phoebetria fusca''), also known to sailors as the Quaker, is a species of marine bird belonging to the albatross family Diomedeidae. It is a medium-sized albatross that sports a sooty-brown or sooty-black color. It can b ...

''), 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 a ...

)'', 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 range overlaps broadly with the range of the related southern giant petrel (''Macronectes giganteus'') ...

''), 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 South ...

albatrosses), the large gray-headed albatross ('' Thalassarche chrysostoma''), 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 earli ...

'') (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 called the lesser sheathbill or paddy bird, is one of only two species of sheathbills, aberrant wader, shorebirds which are terrestrial (land)scavengers of subantarctic islands. Description ...

and many seabirds brown skua, kelp gull ('' Larus dominicanus''), 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, 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). It is a top order predator, feeding on a wide range of prey including cep ...

(''Hydrurga leptonyx''),

Weddell seal The Weddell seal (''Leptonychotes weddellii'') is a relatively large and abundant Earless seal, true seal with a Subantarctic, circumpolar distribution surrounding Antarctica. The Weddell seal was discovered and named in the 1820s during expediti ...

(''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 the only member of the genus ''Lobodon''. They are medium- to large-sized ( ...

(''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 (; : salmon) are any of several list of commercially important fish species, commercially important species of euryhaline ray-finned fish from the genera ''Salmo'' and ''Oncorhynchus'' of the family (biology), family Salmonidae, native ...

, 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. It has been introduced to New Zealand, Australia, Peru, Brazil, Uruguay, Argen ...

, 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 of the Patagonian toothfish ('' Dissostichus eleginoides'') 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