New Iguana Rafted to Fiji
New Species of Iguana Crossed the Pacific on a Raft
The discovery by scientists from the Australian National University School of Botany and Zoology, led by Associate Professor Scott Keogh, with associates from Australia’s Macquarie University and the US Geological Survey in San Diego, means there are three unique species of Brachylophus iguanas on Fiji, not two.
“The iconic Fijian iguanas are famous for their beauty and also their unusual occurrence in the middle of the Pacific Ocean because all of their closest relatives are in the Americas,” Professor Keogh said.
New Iguana Says ‘Hello, Hello’
The new species, a handsome creature with dark green and white stripes on the body and a greeny-gold belly and legs, has been named Brachylophus bulabula.
The scientific name bulabula is a doubling of ‘bula’, the Fijian word for ‘hello,’ making it a more enthusiastic greeting.
The three Brachylopus species are closely related to South American iguanas, despite the immense distances of 13 million years and 8,0000 miles.
“They are the sister group to the other iguanas. The divergence dates to about 13 million years ago, but they are all still part of one big group,” Professor Keogh said.
Iguanas Floated to Fiji on Marine Rafts
The mystery of how the Fijian iguanas originally arrived has long puzzled biogeographers.
The highest islands of Fiji have been above sea level for at least the last 16 million years, and Professor Keogh said the study’s findings suggested that the iguanas, both the extinct species and the three remaining ones, had been living on the islands for much of that time.
“An 8,000 mile rafting trip is the best hypothesis of how they arrived in Fiji, based on all the available evidence,” he said.
“There are lots of records of very large floating piles of plant material after large storms on which the iguanas could have been stranded.”
Humans arrived on Fiji in relatively recent times, only about 3,000 years ago.
Until then, five iguana species had a relatively peaceful life, living in different parts of the forest, browsing on the leaves of many indigenous plants.
Fijian Iguanas on the Endangered List
Humans brought with them animals – cats, mongooses and goats. Two species of Brachylopus were hunted to extinction by the humans, cats and mongooses.
The remaining species are endangered by the animals which are feral on most of the islands. While goats don’t eat iguanas, they do eat the smaller, tender leaves that are food for baby iguanas.
The Fiji crested iguana, Brachylophus vitiensis, is now listed as Critically Endangered on the IUCN Red List.
Similarly to the turtles on the Galapagos Islands, each Fijian island island has its distinctive iguana lineage.
“An important study finding regarding the conservation of the genetic diversity in these iguanas is that, with only one exception, every island for which there were samples was represented by at least one distinct iguana lineage,” Professor Keogh said.
One island has been set aside as refuge for the iguanas, but all the other islands have animals that threaten the iguanas’ survival.
The discovery of Brachylophus bulabula, 'Molecular and morphological analysis of the critically endangered Fijian iguanas reveals cryptic diversity and a complex biogeographic history', was published in a special themed edition of Philosophical Transactions of the Royal Society B, which paid tribute to Charles Darwin’s contribution to the science of Pacific region.
See also: Transvestite Lizards Imitate Females
Fijian Iguana, Brachylophus bulabula.
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