The Gau iguana (''Brachylophus gau'') is a species of

iguana ''Iguana'' (, ) is a genus of herbivorous lizards that are native to tropical areas of Mexico, Central America, South America, and the Caribbean. The genus was first described in 1768 by Austrian naturalist Josephus Nicolaus Laurenti in his bo ...

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

Gau Island Gau (pronounced ) is an island belonging to Fiji's Lomaiviti archipelago. Located at 18.00° S and 179.30 °E, it covers an area of , with a total shoreline that measures long, making it the fifth largest island in the Fijian archipelago. Its ...

in the

Fiji Fiji ( , ,; fj, Viti, ; Fiji Hindi: फ़िजी, ''Fijī''), officially the Republic of Fiji, is an island country in Melanesia, part of Oceania in the South Pacific Ocean. It lies about north-northeast of New Zealand. Fiji consists ...

an archipelago. It mostly lives in the well-preserved upland forests of the island, with smaller populations in the degraded coastal forests. It can be distinguished from other South Pacific iguanas by the male's distinctive color pattern and solid green throat. It is also the smallest of all South Pacific iguanas, being about 13% smaller than the third smallest species and 40% smaller than the largest extant species. The species was first recorded on Gau Island by the Scottish naturalist

John MacGillivray John MacGillivray (18 December 1821 – 6 June 1867) was a Scottish naturalist, active in Australia between 1842 and 1867. MacGillivray was born in Aberdeen, the son of ornithologist William MacGillivray. He took part in three of the Royal Nav ...

in 1854, during his travels on . However, it did not receive a proper species description until 2017. It is considered

endangered An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and inva ...

on the

IUCN Red List The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biol ...

due to the presence of invasive mammalian predators on its island, such as

black rat The black rat (''Rattus rattus''), also known as the roof rat, ship rat, or house rat, is a common long-tailed rodent of the stereotypical rat genus ''Rattus'', in the subfamily Murinae. It likely originated in the Indian subcontinent, but is n ...

s (''Rattus rattus''),

Polynesian rat The Polynesian rat, Pacific rat or little rat (''Rattus exulans''), known to the Māori as ''kiore'', is the third most widespread species of rat in the world behind the brown rat and black rat. The Polynesian rat originated in Southeast Asia, a ...

s (''Rattus exulans''),

feral cat A feral cat or a stray cat is an unowned domestic cat (''Felis catus'') that lives outdoors and avoids human contact: it does not allow itself to be handled or touched, and usually remains hidden from humans. Feral cats may breed over dozens ...

s (''Felis catus''), and free-ranging

goat The goat or domestic goat (''Capra hircus'') is a domesticated species of goat-antelope typically kept as livestock. It was domesticated from the wild goat (''C. aegagrus'') of Southwest Asia and Eastern Europe. The goat is a member of the a ...

s (''Capra hircus''). Forests are frequently burned for agriculture and eventually turn into grassland, accelerating habitat loss.

Climate change In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to E ...

may also play a threat by increasing cyclone intensity; while most native wildlife in Fiji is adapted to cyclones, they can create temporary gaps in the forests that can be taken over by invasive plant and insect species such as ''

Mikania micrantha ''Mikania micrantha'' is a tropical plant in the family Asteraceae; known as bitter vine, climbing hemp vine, or American rope. It is also sometimes called mile-a-minute vine (a moniker also used for the unrelated '' Persicaria perfoliata''). I ...

'' and

yellow crazy ant The yellow crazy ant (''Anoplolepis gracilipes''), also known as the long-legged ant or Maldive ant, is a species of ant, thought to be native to West Africa or Asia. They have been accidentally introduced to numerous places in the world's trop ...

(''Anoplolepis gracilipes''), from which they can expand their range.

References

{{Taxonbar, from=Q33060870 gau Endemic fauna of Fiji Reptiles of Fiji Reptiles described in 2017