May 8

A recent study has found that Australian marsupials such as tree possums, bandicoots and quolls are suffering a sudden decline, placing them at risk of extinction in Australia.

Northern quoll image

The northern quoll is the smallest of the four Australian quoll species

Dramatic decline

Several of Australia’s unusual marsupials, including bandicoots and phascogales, are currently experiencing a dramatic decline in the north of the country, according to recent research. Small mammal species across the continent have been known to be at risk of extinction for some time, but Chris Johnson, a wildlife conservation professor from the University of Tasmania, noted a marked and worrying change in the northern regions of Australia.

There’s a pretty clear picture and it shows that lots of species have declined dramatically,” he said. “Where we can infer the timing of decline, it’s been fairly recent and there are now large areas where small mammals are either very rare or don’t exist but the habitat looks like it should support small mammals.”

Northern brush-tailed phascogale image

The northern brush-tailed phascogale is classified as Vulnerable on the IUCN Red List

Worrying changes

The recent changes have been described by scientists as being a ‘new wave of decline’, but Johnson says that it is not clear how sudden these changes were. The most noticeable declines began in the early 1990s, and were particularly evident in conservation areas such as Kakadu National Park in the Northern Territory. In recent decades, around 20 small native mammal species have disappeared from Kakadu, including bandicoots, northern quolls, tree possums and northern brush-tailed phascogales, and a similar pattern has been seen in other parts of the country.

Western barred bandicoot image

The western barred bandicoot is one marsupial which has already been lost from most of its former range in southern and western Australia

Feline culprits

Scientists analysed information from a database of current mammal populations, comparing the current wave of extinction across different species with past extinction patterns. The researchers reported their findings to a meeting of experts in Canberra this week, revealing that some common factors had emerged.

First, the extinctions are occurring mainly in ground-dwelling animals of small body size which live in open, dry habitat. This points the finger of suspicion strongly at an introduced predator – the cat,” said Johnson. “We have seen similar extinction patterns driven by predators like foxes in southern Australia – so the big question was: ‘Is history repeating itself, or is it something new?’”

Johnson explained that the declines were being seen in species typically eaten by cats, and that, tellingly, no such declines were seen in cat-free regions. However, cats are thought to have been introduced with the settlement of Europeans in the late 1700s, while the noticeable marsupial declines were far more recent, prompting Johnson and his colleagues to ask: what had changed to make cats such a damaging predator?

Dingo image

Professor Johnson suggests boosting local biodiversity through the reintroduction of native predators such as the dingo

Unanswered questions

Typical factors in species decline include the outbreak of disease and habitat loss through land clearance, but neither of these was evident in northern Australia. However, it is thought that the use of fire by cattle ranchers may be having an effect on native marsupial populations.

It is probably no one thing,” said Johnson, “but the data points to a combination of several effects – all of which tend to favour the hunting style adopted by cats which places small ground-dwelling animals at greater risk.”

The creation of sanctuaries in the bush or on offshore islands is one method currently being used to help protect a variety of marsupial species and boost their falling numbers. However, Professor Johnson is also championing a method which involves boosting local biodiversity by allowing the breeding and reintroduction of predators such as dingos to ecosystems where they have been eradicated by humans. It is hoped that, as the native predators replace feral predators or at least reduce their numbers, native prey species will be given the opportunity to rebound and thrive.

Read more on this story at The Telegraph – Australian marsupials such as possums in sudden decline.

View images and videos of Australian species on ARKive.

 

Kathryn Pintus, ARKive Content and Outreach Officer

Jan 26
Photo of northern hairy-nosed wombat

Northern hairy-nosed wombat (Lasiorhinus krefftii)

Species: Northern hairy-nosed wombat (Lasiorhinus krefftii)

Status: Critically Endangered (CR)

Interesting Fact: The northern hairy-nosed wombat has a backwards-facing pouch, ensuring that the pouch does not fill up with soil when the animal is digging.

The northern hairy-nosed wombat is a large, heavily built marsupial with strong claws, which it uses for digging complex burrow systems. The largest of the three wombat species, the northern hairy-nosed wombat is also the largest known herbivorous burrowing mammal. It spends the day sheltering inside its burrow, emerging at night to feed on grasses, and its very low water requirements help it to survive in its hot, dry environment.

One of the world’s rarest mammals, the northern hairy-nosed wombat has declined due to a combination of drought, competition for food with cattle and sheep, habitat loss due to invasive grasses, and predation by dingoes. The Epping Forest National Park in central Queensland, Australia, was created to protect the last remaining population of this species, and cattle and dingoes have been excluded from the area. Various conservation efforts are underway to try and save the northern hairy-nosed wombat, and a second population has now been established in southern Queensland. Although this rare marsupial is still perilously close to extinction, its population has risen from fewer than 40 individuals in the 1980s to around 200 by 2012.

Find out more about the northern hairy-nosed wombat and its conservation at EDGE – Northern hairy nosed wombat and The Wombat Foundation.

See images and videos of northern hairy-nosed wombat on ARKive.

Liz Shaw, ARKive Text Author

Jan 26
Australia Day is an annual celebration held on the 26th January every year to mark the first arrival of ships in Sydney Cove from Great Britain in 1788. Every year on the eve of Australia Day, the Australian of the Year awards are given out. To celebrate, we thought we would give out some of our own awards to the animals found in Australia.
 

Most unique appearance

There are some very unusual looking animals in Australia, making this a tough category. Strong contenders included the Javanese cownose ray and the narrow-breasted snake-necked turtle. However the award went to the platypus; a creature so unusual looking that the first specimens brought back to England were though to be the work of a fraudulent taxidermist! With its duck-like bill, webbed feet and broad flattened tail, the platypus certainly has a very distinctive and unusual appearance.

Platypus photo

The platypus has a very unique appearance with its duck-like bill, webbed feet and broad flattened tail

 

Best camouflage

The winner of this award, the pygmy seahorse, is so well camouflaged in its coral reef habitat it was not discovered until the coral in which it lives in was being examined in a lab! The pygmy seahorse is found in the coral reefs around Australia, and it is not only the same colour as the coral in which it lives, it is also covered in small swellings which resemble the polyps of the coral. This results in the seahorse being very well camouflaged. Can you see the pygmy seahorse in the picture below?

Pygmy seahorse photo

Can you spot the pygmy seahorse?

Most dangerous

Australia is renowned for having some of the world’s most dangerous animals! There are poisonous snakes, spiders, jellyfish, sharks, crocodiles even the platypus has a venomous spur on the back of its rear ankles! However this award goes to one of Australia’s less well known venomous animals – the southern blue ringed octopus. This octopus may be small in size, but it has enough venom in its saliva to kill 26 adults! Its venom, which contains tetrodotoxin, causes neurological problems such as breathing troubles and paralysis. Normally brown in appearance, when threatened it develops blue ringed shape markings. There is currently no antivenom available for the blue ringed octopus.

Southern blue ringed octopus

Southern blue ringed octopus displaying its blue ringed shape markings

Best dressed

Colouration in animals has a wide range of functions. Whether for defence or for attracting a mate, Australia has some beautifully coloured animals including the sunset frog with its bright orange belly, and the multicoloured superb parrot. However the winner of this award is the Gouldian finch. This multicoloured finch, endemic to northern Australia, has a green body, a blue rump, a purple breast, a yellow belly and a red, black or yellow head. The very colourful adults are however upstaged by the chicks with their elaborate and colourful blue, yellow, black and white gape.

Gouldian finch chick

Gouldian finch chick gape

Life time contribution award

This category was very difficult with Australia having so many iconic animals. In the end, the winner was the koala. Koalas, endemic to Australia, are one of Australia’s best known animals. Though bear like in appearance the koala is actually a marsupial. The koala is mainly nocturnal, spending most of its time up in the trees where it can feed and rest, whilst gaining some protection. Koalas have fairly sedentary lifestyles with their diet mainly consisting of eucalyptus leaves. Koalas vary depending on where about in Australia they are found, and those found in south Australia are larger and have thicker fur than those in the north.

Photo of a koala relaxing in a tree

This koala is relaxing after its big win!

 

The Auzzie award

Like the Oscars have the Razzies, we have our own Auzzie award to give out.

Most unusual faeces

This result was unanimous - it had to go the wombat for having cubic poo!

Photo of a northern hairy-nosed wombat

This northern hairy-nosed wombat does not seem to want to collect its award!

Happy Australia day!

Let us know of any other awards you would like to give out to other Australian species.

Jemma Pealing, ARKive Media Researcher

May 1

The koala has been listed as a threatened species in parts of Australia due to its shrinking population, according to officials.

Photo of koala sleeping

Koala sleeping

Koalas under threat

One of Australia’s most iconic marsupials, the koala is facing a range of threats, including habitat loss, urban expansion, dog attacks, vehicle collisions and disease. Its specialised diet of eucalyptus leaves confines it to quite specific habitats, while increasing carbon dioxide levels in the atmosphere may be reducing the nutrient content of the leaves it eats.

Climate change is also increasing the risk of drought and fires, with koalas being particularly vulnerable to bushfires as their slow movements and tree-dwelling lifestyle make it difficult for them to escape.

Photo of koala eating eucalyptus leaves

Koala eating eucalyptus leaves

Although the koala’s exact population size is unclear, in New South Wales and Queensland its numbers are believed to have fallen by as much as 40% since 1990.

Iconic species

Under the new listing, koalas in Queensland, New South Wales and the Australian Capital Territory will be considered ‘vulnerable’ on Australia’s national list of threatened species. Extra funding will be given to develop new survey methods for koalas and find out more about koala habitat.

According to the Australian Environment Minister, Tony Burke, the decision to list the koala as vulnerable followed a “rigorous scientific assessment”.

Photo of koala joey feeding on eucalyptus leaves

Koala joey feeding on eucalyptus leaves

We’re talking about a species that is not only iconic in Australia, but is known worldwide, a species that has taken a massive hit over the last 20 years and we can’t wait any longer before we turn the corner when the scientists are telling us the evidence is in,” he said.

Koalas are an iconic Australian animal and they hold a special place in the community… People have made it very clear to me that they want to make sure the koala is protected for future generations.”

Varying populations

The listing does not cover the whole of Australia, with koala populations in some areas thought to be larger and stable or even increasing.

Photo of a koala

Koala

However, conservationists, including Deborah Tabart of the Australian Koala Foundation, have argued that the koala should be protected nationwide. Although the new listing may be a step in the right direction, the koala still faces many threats and the future of this Australian icon is far from secure.

Read more on this story at BBC News and the Australian Government media release.

Find out more about koala conservation at the Australian Koala Foundation.

View more photos and videos of the koala on ARKive.

Liz Shaw, ARKive Species Text Author

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