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

Nov 23
Image of bridled nailtail wallaby

Bridled nailtail wallaby (Onychogalea fraenata)

Species: Bridled nailtail wallaby (Onychogalea fraenata)

Status: Endangered (EN)

Interesting Fact: The bridled nailtail wallaby gets its name from the white ‘bridle’ line running down the centre of the neck and behind each arm, and from the horn-like ‘nail’ point on the tip of its long tail.

More information:

The bridled nailtail wallaby has earned the nickname ‘flash jack’ thanks to its ability to hop extremely quickly. It is able to pick up food, open its pouch and groom using its small forearms. Adult and young wallabies – both male and female – are similar in appearance, with grey fur and darker paws, feet and tail. Bridled nailtail wallabies are nocturnal and spend most of the day sheltering in shallow nests. At night, they tentatively come out to feed in open grassy woodlands.

Born around May, the young wallaby is tiny and underdeveloped, with rudimentary limbs and tail, and closed ears and eyes. However, once its umbilical cord breaks, it crawls at an amazing speed up through the female’s fur to the safety of her pouch, where it suckles for up to 11 months.

The bridled nailtail wallaby was common in inland Australia in the mid-19th century, but populations decreased dramatically and by the 1960s this species was presumed extinct. A small population was rediscovered in 1973 in a 100 km² area in central Queensland, Australia, and this is the only place in the world this species of wallaby is now found, having been lost from 95% of its original range. It is difficult to isolate any single cause for the decline of the bridled nailtail wallaby, as it has occurred so rapidly. In the early 1900s, this species suffered dramatically from shooting for its fur and pest control. Other threats include wildfires, drought, over-predation by foxes, feral cats and dingoes, disease, habitat destruction by the pastoral industry and competition for food from grazers such as rabbits and domestic sheep.

Captive breeding and translocation projects have been developed, in addition to a recovery plan, but the public’s understanding of this species’ plight must also be increased to ensure continued support for the bridled nailtail wallaby.

 

Find out more about the bridled nailtail wallaby at the Wildlife Preservation Society of Queensland and the Bridled Nailtail Wallaby Trust.

See images and videos of the bridled nailtail wallaby on ARKive.

 

Phoebe Shaw Stewart, ARKive Text Author

Sep 7
Photo of Carnaby's black-cockatoo feeding

Carnaby’s black-cockatoo (Calyptorhynchus latirostris)

Species: Carnaby’s black-cockatoo (Calyptorhynchus latirostris)

Status: Endangered (EN)

Interesting Fact: Carnaby’s black-cockatoo can potentially live for 40 to 50 years in the wild.

More information:

Carnaby’s black-cockatoo is a large, black cockatoo found only in south-western parts of Western Australia. This species generally breeds in dry eucalypt woodland and forages in nearby heath and scrubland, although it has also adapted to plantations of non-native pines. Its diet consists mainly of seeds, although it also takes some fruit, nectar and insect larvae. Hard fruit cases are crushed in the short, powerful beak to access the seeds inside. Carnaby’s black-cockatoo is a sociable species and may form large flocks outside of the breeding season, when many individuals move to wetter coastal areas. Pairs mate for life and nest in hollows in large eucalypt trees, where they lay clutches of two eggs. Typically, the second chick dies soon after hatching and only one chick is raised.

Carnaby’s black-cockatoo has undergone a significant decline in the last century, vanishing from much of its former range. The main cause of this decline is the widespread clearance, fragmentation and degradation of its habitat. The large trees this species uses for nesting are failing to regenerate due to overgrazing by sheep and rabbits, while the clearance of important feeding habitat around breeding sites means adults have to travel further to find enough food for their chicks. Carnaby’s black-cockatoo is also sometimes illegally captured for the pet trade, and is often killed in collisions with cars. Fortunately, a number of conservation measures are in place to protect this large parrot. Captive breeding is underway, and Carnaby’s black-cockatoo is legally protected in the wild. Key areas of habitat are being protected and restored, and BirdLife Australia runs a survey known as the ‘Great Cocky Count’ to map this species’ populations.

 

Find out more about Carnaby’s black-cockatoo at WWF Australia and the Australian Government.

See images and videos of Carnaby’s black-cockatoo on ARKive.

Liz Shaw, ARKive Text Author

Aug 30

Beyond the signature kangaroo or koala, did you know that Australia is also home to a wide range of lesser-known and somewhat bizarre-looking species such as the spotted handfish or the southern hairy-nosed wombat?  With astounding habitats including Barrow Island, the Great Barrier Reef, and the outback, we thought we would take the opportunity to highlight just some of the unique species found in this spectacular land!

Weedy wader Leafy seadragon swimming

The leafy seadragon is endemic to Australia, meaning it is found nowhere else on Earth. Living in shallow coastal waters, these slow-moving creatures call underwater seagrass meadows home, blending in perfectly due to their leaf-like appendages.

King croc

Immature saltwater crocodile swimming underwater

The largest of all crocodilians, the saltwater crocodile roams both the land and sea. By using its powerful tail and webbed hind feet, this species is an effective aquatic predator. The saltwater crocodile feasts on large land animals such as wallabies, dingoes, and even humans!

The face of climate change

Found only in northern Australia, the lemuroid ringtail possum may become Australia’s first victim of global climate change. Being unable to withstand temperatures over 86°F (30°C), this species is extremely vulnerable to heatwaves, which are expected to increase in frequency as the climate changes. In fact, a heatwave in 2005 was thought to have wiped out the entire population until a few individuals were finally discovered in 2009.

Misunderstood marsupial

Adult Tasmanian devil

Known for its frightening nocturnal screeches, the Tasmanian devil is the largest of the carnivorous marsupials. Contrary to its savage reputation, the Tasmanian devil is actually quite shy and is only aggressive when feeling threatened or when in competition with other devils.

Snack and swim

Dugong with remoras

Strictly feeding on plants, the dugong is often referred to as the ‘sea cow’, but it is actually more closely related to elephants than cows! Found off the coast of northern Australia, the dugong uses its flexible upper lip to rip whole plants apart, leaving ‘feeding trails’ on the sea floor. What a messy eater!

Water-free wallaby

Black-footed rock wallaby with young on rock

Found throughout Australia, the black-footed wallaby lives its life in groups of 10 to 100 individuals. Found primarily in rock piles and granite outcrops, this wallaby feasts mostly on grasses and fruit, and, interestingly, obtains nearly all of its water through its food.

Burrow builder

Southern hairy-nosed wombat

An expert digger, the southern hairy-nosed wombat is able to construct burrows that support a constant inside temperature of 78°F in the summer and 57.2 °F in the winter. These burrows are often formed as networks of up to thirty meters long that can host five to ten wombats.

Smooth sailing

Sugar glider on branch preparing to leap

The softly furred sugar glider uses the membrane along its body to glide distances of up to 150 feet between trees. This agile possum also has a rather distinctive alarm call, which is said to resemble a yapping dog!

Cultural croaker

Northern corroboree frog

Found only in the northern Australian Alps and the Australian Capital Territory, the northern corroboree frog has a local cultural story attached to its name. ‘Corroboree’ is an aboriginal word used to describe a gathering, where traditionally attendees are adorned with brightly colored yellow markings similar to those of this frog.

Aquatic ambler

Spotted handfish

A fish with ‘hands’ that can walk the ocean floor? It’s true! The spotted handfish, one of the world’s most endangered fish, is able to use its characteristic ‘hand-like’ fins to walk the sea floor, occasionally sucking on prey like shrimp and small fish. Threatened by development, a restricted distribution and a low reproductive rate, the spotted handfish population may be restored in the future through successful re-introduction programs.

If you’re looking to continue your ‘walkabout’ around Australia on ARKive, check out the new Barrow Island topic page or search the 1,200+ Australian species on ARKive today. Feel free to share your favorite Aussie species in the comments below!

Jade Womack, Education & Outreach Intern, Wildscreen USA

Aug 19

We’ve recently added some fantastic images to ARKive from one of our new media donors, Heath Holden, and we jumped at the opportunity to hear a little more from Heath about his work.

Can you tell us about yourself and give us a bit of a run down on your photographic background?

Hi! I’m Heath Holden, I work as a freelance photographer and photojournalist for various clients around Tasmania and also interstate. I started out shooting photos of my friends riding BMX and a few landscapes when we went away on trips to the USA, Canada etc… there is so much beauty out there in this world. I guess it all snowballed from there wanting to take better shots and learn more about the art. My first real photography job was for a daily newspaper here in north west Tasmania, The Advocate. I worked here for about 18 months covering news, sport, features etc. During this time I learnt a lot about photography, those little tricks and techniques I’ll never forget. Work slowed a bit when the financial crisis hit town, I had some choices to make and left Tasmania for a staff job with Wildlife Reserves Singapore (parent company of the Singapore Zoo, Jurong Bird Park, Night Safari and now River Safari) as the in-house photographer, documenting all the zoological procedures which were then sent out for editorial use around S.E Asia. I also worked with the advertising and promotions department shooting the work for campaigns and other commercial needs, image archiving, educational content etc…

My work is represented by Lonely Planet Images, (which is now handled by Getty Images).

Brown bear photo

Your recent contribution to ARKive’s collection contained some fresh Tasmanian devil images, how did you come about the idea of photographing Tasmanian devils like this?

I had the idea while still living in Singapore, I knew I would leave once my contract was finished so I started to think of meaningful photography projects which were unique and technically challenging, and the Tasmanian devil came to mind straight away. It’s very unique and also facing a challenging future due to the facial tumour disease spreading. After searching the internet and various photo libraries for Tasmanian devil images which were shot purely in the wild (this was an important factor to me) under natural conditions (no bait) which had some kind of wow factor, I found very little. This was it, I knew I had to do it!

Tasmanian devil photo

Sounds like quite a learning process! What’s been the biggest hurdle in this project?

Well… hurdles huh, how much time do we have? I shot an email to an old friend who is a zoologist and works with devils, told him my idea and he said I’d need to use camera traps, basically no other way to do it. I had no idea about these at all or where to look! The bag of worms was about to open… (Internet search then fast forward a bit). Studying videos of snow leopards and tigers being documented with camera traps, I started breaking them down to get some kind of idea of equipment and techniques used by others. I soon bought some infra-red sensors/triggers and the hunt for the more gear began! There have been many little hurdles along the way, waterproofing, locking, sync cables and splitters for multiple flashes, flash misfires and dead batteries… I eventually worked out which flashes to use saving me lugging a load of batteries out every morning to fill the battery packs, 12 AAs! That gets tiring, also there is this fancy cable I need to get which will hopefully solve the problem of missing the first shot while the flash comes to life. Lighting is very important with this project, Tasmanian devils being nocturnal almost never wander around in daylight so it’s always crucial for the flashes to work when I want them to. Generally the issues are getting smaller the further I go and I’m feeling very in control of the setup now, in the beginning I would setup and think “oh I hope it works” but now I know it will work. I used to be a mechanic for about 6 years so I feel fairly handy when it comes to making housings for my cameras and strobes. I have a buddy who’s a great sheet metal worker and welder, he whipped up a couple of alloy boxes for me which I then crafted into a nice housing to fit mid range DSLR cameras and 14mm lens.

Tasmanian devil photo

Are there any projects in the pipeline, or species you’d like to focus on in the future?

Definitely, I’ll be working on more projects all the time to grow my portfolio and skills to the highest possible level. The aim of my work is to create unique images of wildlife and nature which stand out from what people have already seen, in terms of new angles, techniques and overall image quality. I want readers to be stunned with amazement! My devil work as an example – yes, there are plenty of scientists and organisations here camera trapping, but they’re only using the basic trail cam setups which really are no good for reproduction at an editorial level, that’s where the skills of a photographer come in to play, to UP the quality for the show, not just for monitoring purposes. As for species, I’d like to do some work on the Tasmanian wedge-tailed eagle, this is a sub-species, but larger than the more common wedge-tailed eagle. These birds are huge with a possible wingspan of over 2 metres, and they are wise, getting close is very tough! I like a challenge so this could be the next one.

Short-beaked echidna photo

What role do you think wildlife photography can play in conservation?

Wildlife photography is extremely important in conservation and awareness now, and it is getting more important every day, it really is the only voice the animals have. Photography helps raise public awareness in visual ways that scientific data can’t, it triggers emotion and a direct connection. We need to be smart in the way we use natural resources and find a healthy balance, we can all live on this planet but we need to look after it and not let money, greed and endless corporate growth drive everything to self destruction.

Australian pelican photo

Heath Holden.
0487 407 901. (Australian code is +61)

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