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Distant quoll could be long lost Aussie
July 25, 2007
New Guinean bronze quoll
Scientists say that New Guinea's bronze quoll might be an immigrant Australian that was isolated from the mainland by rising sea levels caused by climate change.
Eighteen thousand years ago and for 90% of the last 250,000 years, Australia and New Guinea shared a land bridge that allowed animals and people free passage in both directions.
But 6,000 to 8,000 years ago, warmer temperatures, glacial melting and rising seas closed the land bridge, effectively "stranding
Now, new genetic research by UNSW biologists Karen Firestone and Steve Hamilton reveal that the bronze and western quolls may be the same creature. The two marsupials share 98 per cent of some parts of their DNA in common and are more similar genetically than any of Australia's four quoll species (the western, northern, eastern and spotted-tail).
"It's preliminary finding supported by Firestone's and other scientists work but comparative similarities suggest that the two species share a relatively recent common ancestry," says PhD student Steve Hamilton, who recently returned from the TransFly Savannas of Southern New Guinea where he made a six-month study of quolls.
"Genetical
Discovered in 1979, the New Guinean bronze quoll was first thought to be an isolated population of the western quoll. About the size of a small cat, the animal has a rust coloured pelt with white spots, weighs up to 1.3kg and measure 70cms when fully grown. In 1988 the animal was classified as a distinct species, based on differences in skull size and other body differences.
Australian western quolls -- - which are brown coloured, with conspicuous white spots -- - once occuredoccurred across 80% of the continent. Today, they survive only in the far south-west of Western Australia, living in jarrah forests, drier woodlands and mallee scrub.
Until now, the little that is known about bronze quolls has come from just five specimens held by different museums around the world.
However, the latest findings are based on fresh tissue samples (ear biopsies) the UNSW scientists took from 14 additional bronze quolls. The fleet-footed creatures are notoriously difficult to observe and trap in the wild.
Hamilton and Firestone caught the elusive animals with novel lightweight traps and help from local tribesmen, who rely on hunting and farming skills for food.
"We relied on the knowledge and support of the local people to collect samples," says Steve Hamilton, who says there are still folklore stories among the villagers about the time when it was possible to walk across the land bridge that once connected New Guinea to Australia.
New Guinea: a time capsule of Australia's past
Scientists believe marsupials diverged from mammals in North America around 90 million years ago, and later made their way to Australia when it was part of Gondwanaland, the super-continent that included Antarctica, Africa, South America, New Zealand and New Guinea.
After much of Gondwanaland had broken apart, Australia began drifting northward until it collided 15 million years ago with the Pacific Plate that created the new geological land of New Guinea.
This newly formed land bridge allowed a "time capsule" of Australian marsupials and other flora and fauna to colonise New Guinea.
As Australia continued drifting northward, it pushed up what are now the New Guinean highlands. This eventually created a "rain shadow" effect that caused the dry weather conditions we still experience in Australia today.
Over time, many of Australia's plants and animals evolved or died out in response to the warmer drier conditions, which is why New Guinea's flora and fauna are like a snapshot of the past.
According to Hamilton, the region is one of the most distinctive eco-regions in Australasia because of its blend of Australian and New Guinea species and its mosaic of dry savannas, interspersed with monsoon forest and extensive wetlands.
"There are at least 44 mammals found just across Torres Strait in the TransFly Savannas of Southern New Guinea that can also be found in Northern Australia," he says.
These include Agile Wallabies, Northern Brown Bandicoots, Short-beaked Echidnas, Red-legged Pademelons, Spectacled-hare Wallabies, Red-cheeked Dunnart, Brush-tailed Rabbit Rats, Cape York Rats, Water Rats, Sugar Gliders, Little Red Flying Foxes and a number of other bat species.
"We also encountered some less commonly encountered species that haven't been seen for 50 years and others that had never been reported from that part of New Guinea.
"We're still examining material that may prove that some mammals in this area are uniquely different from those in the rest of New Guinea and Australia," says Hamilton.
July 25, 2007
New Guinean bronze quoll
Eighteen thousand years ago and for 90% of the last 250,000 years, Australia and New Guinea shared a land bridge that allowed animals and people free passage in both directions.
But 6,000 to 8,000 years ago, warmer temperatures, glacial melting and rising seas closed the land bridge, effectively "stranding
Now, new genetic research by UNSW biologists Karen Firestone and Steve Hamilton reveal that the bronze and western quolls may be the same creature. The two marsupials share 98 per cent of some parts of their DNA in common and are more similar genetically than any of Australia's four quoll species (the western, northern, eastern and spotted-tail).
"It's preliminary finding supported by Firestone's and other scientists work but comparative similarities suggest that the two species share a relatively recent common ancestry," says PhD student Steve Hamilton, who recently returned from the TransFly Savannas of Southern New Guinea where he made a six-month study of quolls.
"Genetical
Discovered in 1979, the New Guinean bronze quoll was first thought to be an isolated population of the western quoll. About the size of a small cat, the animal has a rust coloured pelt with white spots, weighs up to 1.3kg and measure 70cms when fully grown. In 1988 the animal was classified as a distinct species, based on differences in skull size and other body differences.
Australian western quolls -- - which are brown coloured, with conspicuous white spots -- - once occuredoccurred across 80% of the continent. Today, they survive only in the far south-west of Western Australia, living in jarrah forests, drier woodlands and mallee scrub.
Until now, the little that is known about bronze quolls has come from just five specimens held by different museums around the world.
However, the latest findings are based on fresh tissue samples (ear biopsies) the UNSW scientists took from 14 additional bronze quolls. The fleet-footed creatures are notoriously difficult to observe and trap in the wild.
Hamilton and Firestone caught the elusive animals with novel lightweight traps and help from local tribesmen, who rely on hunting and farming skills for food.
"We relied on the knowledge and support of the local people to collect samples," says Steve Hamilton, who says there are still folklore stories among the villagers about the time when it was possible to walk across the land bridge that once connected New Guinea to Australia.
New Guinea: a time capsule of Australia's past
Scientists believe marsupials diverged from mammals in North America around 90 million years ago, and later made their way to Australia when it was part of Gondwanaland, the super-continent that included Antarctica, Africa, South America, New Zealand and New Guinea.
After much of Gondwanaland had broken apart, Australia began drifting northward until it collided 15 million years ago with the Pacific Plate that created the new geological land of New Guinea.
This newly formed land bridge allowed a "time capsule" of Australian marsupials and other flora and fauna to colonise New Guinea.
As Australia continued drifting northward, it pushed up what are now the New Guinean highlands. This eventually created a "rain shadow" effect that caused the dry weather conditions we still experience in Australia today.
Over time, many of Australia's plants and animals evolved or died out in response to the warmer drier conditions, which is why New Guinea's flora and fauna are like a snapshot of the past.
According to Hamilton, the region is one of the most distinctive eco-regions in Australasia because of its blend of Australian and New Guinea species and its mosaic of dry savannas, interspersed with monsoon forest and extensive wetlands.
"There are at least 44 mammals found just across Torres Strait in the TransFly Savannas of Southern New Guinea that can also be found in Northern Australia," he says.
These include Agile Wallabies, Northern Brown Bandicoots, Short-beaked Echidnas, Red-legged Pademelons, Spectacled-hare Wallabies, Red-cheeked Dunnart, Brush-tailed Rabbit Rats, Cape York Rats, Water Rats, Sugar Gliders, Little Red Flying Foxes and a number of other bat species.
"We also encountered some less commonly encountered species that haven't been seen for 50 years and others that had never been reported from that part of New Guinea.
"We're still examining material that may prove that some mammals in this area are uniquely different from those in the rest of New Guinea and Australia," says Hamilton.
