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Tuesday, May 5, 2015

Australia: Rare Mammals by Night

Australia once teemed with marsupials. When humans first arrived here some 40,000 years ago, they met herds of rhinoceros-sized wombat relatives, giant short-faced kangaroos, and marsupial equivalents of lions, wolves and tapirs. These are all long gone, perhaps helped on their way by our ancestors, except for the 'wolf' or Thylacine (Thylacinus cyanocephalus) which survived into the twentieth century. 

Their disappearance is tragic but, given the fate of Ice Age megafauna the world over, perhaps not surprising. More unexpected has been the far more recent extinction, or near-extinction, of many of Australia's small mammals. Even creatures of remote deserts, such as the Desert Rat-Kangaroo (Caloprymnus campestris) and Pig-footed Bandicoot (Chaeropus ecaudatus), have vanished altogether, and others survive only in increasingly-diminishing mainland refuges or small offshore islands. The chief culprits are creatures humans brought to Australia and now are legion there, including particularly domestic cats and foxes.  These invaders have swept across the continent, devouring any medium-sized, ground-living marsupial in their path. 

It was to see some of the survivors of this marsupial holocaust that we made an overnight stop, on the night of September 13, 2013, at Barna Mia (pronounced My-a), a wildlife refuge in the Dryandra Woodlands near Narrogin, some 280 kilometers north of Albany. 

Visiting Barna Mia requires an advance reservation, and we had to be there before nightfall to reach our accommodations at the Lions Dryandra Woodland Village (which came open only at the last minute, thanks to the kindness of the owners and a cancellation by guests at a wedding party). 

Western Grey Kangaroo (Macropus fuliginosus)
Western Grey Kangaroo (Macropus fuliginosus)
The largest mammals in the area did not need the protection of the sanctuary - they were simply too big to have to worry much about foxes. 

Western Grey Kangaroo (Macropus fuliginosus)
Western Grey Kangaroo (Macropus fuliginosus)
As dusk approached, Western Grey Kangaroos (Macropus fuliginosus) assembled in increasing numbers in the paddock opposite the refuge parking area.

Western Grey Kangaroo (Macropus fuliginosus)
Western Grey Kangaroo (Macropus fuliginosus)
The larger kangaroos are more nocturnal, or at least crepuscular, than many people think (that is why your insurance doesn't cover rental cars in Western Australia if you drive on rural roads after dark).

Western Grey Kangaroo (Macropus fuliginosus)
The kangaroo mob included joeys, some of them out of the pouch but still welcome back for a nurse. 

Australian Ringneck (Barnardius zonarius)
Australian Ringneck (Barnardius zonarius)
While we watched the kangaroos, I took the opportunity to photograph a Twenty-Eight Parrot or Australian Ringneck (Barnardius zonarius) in the glow of the late afternoon sunlight.

To see the Barna Mia specialties, we had to meet our guide, follow him down a long dirt road through the woodlands, and enter, strictly escorted, through a gate into the refuge itself. 

Barna Mia is not, strictly speaking, purely a nature reserve - and that is fortunate for the animals that live there. Though it lies deep in a large natural woodland, the refuge itself is a fenced-in area only four hectares, cut off from the woods surrounding it. The animals it protects were already long gone from this part of Australia, and had to be brought here from their few surviving populations elsewhere. It soon became clear that, for them, roaming free was not an option. Available habitat wasn't the biggest problem; introduced predators were. Removing them meant launching a poison-bait campaign. 

An orientation lecture, beneath a mural of animals that live (or used to live) in the area, gave us the rest of the story.  In Western Australia, poison campaigns against introduced foxes or cats are aided by a biological peculiarity.  The chief ingredient of 1080, the poison of choice for these campaigns, is monofluoroacetic acid.  Many Western Australian members of the genus Gastrolobium, the so-called poisons or poison-peas, are naturally laced with the stuff.  Native mammals, or at least native herbivores, are immune to it, but introduced mammals are not.  That means that poisons can be scattered with relative impunity (pets aside, of course) without being concerned that they will leave a trail of dead marsupials (notably the extremely rare Numbat (Myrmecobius fasciatus), for which Dryandra Woodlands is one of the few remaining strongholds) in their wake. 

In fact the campaign against foxes was remarkably successful. Unfortunately for the native species, however, the success proved a boon for feral cats, one of the former items on the foxes' menu. The cat population increased, and put paid to any plan to let the rare mammals brought to Barna Mia out into the unfenced woodlands.

Within the walls of the fence are five of Australia's rarest mammals. We saw four of them, missing only the Quenda, the endangered western race of the Southern Brown Bandicoot (Isoodon obesulus). Oddly, within the reserve the Quenda is the commonest of the five. If I had to miss a species, though, the Quenda was the one, as I have seen other Brown Bandicoots in Eastern Australia and this one does not look that different. 

The animals at Barna Mia are not strictly wild. They are fed, as much to keep tabs on them as to give visitors a better chance to see them. The trick, for visitors, is to sit quietly by the feeding trays, with only a red-light torch for illumination, and wait. Photography is fine, but flash is strictly forbidden.  I have decided here that the animals show better, not in the red glow of the torchlight, but in black-and-white. Their true colours were not visible anyway. 

Rufous hare-wallaby (Lagorchestes hirsutus)
Quendas aside, we were lucky: the first animal to hop into our torchlight was the shyest of the lot. The Rufous Hare-Wallaby or Mala (Lagorchestes hirsutus) is extinct on the Australian mainland. It survives naturally only on two small islands off the West Australian coast, each with its own subspecies.  The subspecies that once lived in the southwest is totally extinct; the animals at Barna Mia come from a captive population, and belong to an undescribed subspecies once widespread in Australia's central deserts.

Rufous hare-wallaby (Lagorchestes hirsutus)
Rufous hare-wallaby (Lagorchestes hirsutus)
It is s charming and dainty little creature, to my mind the most attractive of the three kangaroo species we were to see, and I am sorry that we did not have longer with it.

Rufous hare-wallaby (Lagorchestes hirsutus)
Rufous hare-wallaby (Lagorchestes hirsutus)
The decline of the Rufous Hare-Wallaby in the wild has been blamed on habitat destruction by hordes of invasive rabbits, coupled with extensive wildfires.  Foxes and cats probably finished off the survivors.  Rabbits are under control in Australia today, but wildfires remain a threat to any populations that conservationists hope to reestablish; the last wild population on the mainland, about thirty animals, was wiped out by a wildfire as recently as 1991.  The descendants of animals removed from this population in 1980 have been used to found colonies in fenced-in enclosures elsewhere, and on an offshore island, Trimouille, that was used by the British as a nuclear weapons test site in the 1950s.

Rufous hare-wallaby (Lagorchestes hirsutus)
The Mala is actually a quite colourful little animal, though of course we couldn't tell that under the red torchlight.

I've added a bit of video so you can see each of the Barna Mia marsupials in action.  Here is the Rufous Hare-Wallaby.

Bilby (Macrotis lagotis)
Bilby (Macrotis lagotis)
I was charmed by the Hare-Wallaby, but it was when a second animal wandered into the spotlight that I fell in love.  I had seen plenty of pictures of the Greater Bilby or Dalgyte (Macrotis lagotis), but none prepared me for the living creature. Since all I can offer here are pictures, too, please take it from me that this is one of the leading candidates for the title of Cutest Mammal on Earth. In Australia its image is sometimes used as a substitute for the Easter Bunny.

Bilby (Macrotis lagotis)Bilby (Macrotis lagotis)
This is, in fact, an animal that one requires an act of will not to cuddle. I imagine the feeling would not be mutual, though - this is not, despite its irresistible appearance, a candidate for the next exotic pet craze (though considering there is a craze for Slow Lorises, animals that have not only sharp teeth but a venomous bite, one never knows).

Bilby (Macrotis lagotis)
 Bilby (Macrotis lagotis)
The Greater Bilby is a bandicoot (it used to be called the Rabbit-eared Bandicoot), but such an odd one that it has been placed in a separate family, Thylacomyidae. It is now that family's only survivor. There was once a Lesser Bilby (Macrotis leucura), smaller and less distinctly marked than the Greater, that roamed the northern reaches of Australia's central deserts, but it has not been seen since 1931 (though it may have survived until the 1960s).

Bilby (Macrotis lagotis)
The Greater Bilby is certainly more numerous than the Rufous Hare-Wallaby - there may be 10,000 of them throughout Australia - but they live in scattered populations that are vulnerable and in decline.  Their native range is now largely confined to the northwest, far from Barna Mia, though it once occurred almost throughout the drier parts of the continent.

Bilby (Macrotis lagotis)
 Bilby (Macrotis lagotis)
Bilbies are expert burrowers, and spend their time above ground snuffling about after seeds, insects and fungi, lapping them up with their long tongues (hence, I presume, their rather thin and weak-looking muzzles, which nonetheless seem idea for probing into dark corners).


Here's some Bilby video. Adorable, eh?

Woylie (Bettongia penicillata)
The remaining two rarities at Barna Mia are a pair of small kangaroos, once called rat-kangaroos but now, more attractively, known as bettongs. With the potoroos (Potorous) and the extinct Desert Rat-Kangaroo, they are now placed in a family, Potoroidae, separate from the typical kangaroos (Macropodidae, including the Mala and the Western Grey).  The Woylie or Brush-tailed Bettong (Bettongia penicillata) is the daintier and longer-tailed of the two.  You can see the black brush on the top of its tail that gives it the longer of its common names.

Woylie (Bettongia penicillata)
It is an odder animal than its appearance might suggest.  It lives almost entirely on subterranean fungi, which it sniffs out, digs up with its foreclaws, and digests with a specialized, bacteria-laden stomach.  It builds nests out of tussock grass, carrying the nesting material around wrapped in its prehensile tail.  Once widespread, it was devastated by extensive destruction of its habitat and losses to introduced predators.

Woylie (Bettongia penicillata)
Woylie populations rebounded, after extensive translocation and conservation efforts, from less than 2000 to some 40000 by 2001.  It was even removed from Australian threatened species lists.  Unfortunately, since then it has  undergone a precipitous decline, falling in numbers by over 90 percent.  The Woylie is now categorized as Critically Endangered.  Disease, and predation by cats, may be responsible for its recent collapse.

Here is video of one of the few remaining Woylies.

Boodie (Bettongia lesueur)
The Boodie or Burrowing Bettong (Bettongia lesueur) is a heavier-set and shorter-tailed animal than the Woylie.  Like the Rufous Rat-Kangaroo, it is now extinct in the wild on the Australian mainland.  Natural populations survive only on three Western Australian islands, two of them - Bernier and Dorre - also the last refuge of the Rufous Rat-Kangaroo.

Boodie (Bettongia lesueur)
Boodie (Bettongia lesueur)
Burrowing isn't a habit that you would normally associate with a kangaroo, but Boodies do indeed construct everything from single burrows to extensive interconnected warrens that can hold up to 100 animals.  Their stout forelimbs are adapted to digging, and perhaps their stocky bodies are also testament to their earth-moving capabilities. 
 
The conservation history of the Boodie is similar to that of the other Barna Mia kengaroos: wiped out by introduced foxes and cats, it has been introduced to several offshore islands, and to fenced enclosures on the mainland within its former range (not including Barna Mia, which qualifies more as a captive breeding centre).

Boodie (Bettongia lesueur)
The question of what to call all these animals, at least in English, raises issues of biology, colonial history, native rights, and any number of other interesting social and scientific issues. Early European naturalists, faced with creatures that like if which they had never seen before, struggled with ways to describe and name them based on the animals they already knew. Thus we had the water mole (now the Platypus), the native bear (now the Koala), etc. 

Boodie (Bettongia lesueur)
Other Australian natives became known as, among other things, cats, mice, wolves, and what have you. A few native names did creep in, in particular kangaroo (I suspect, in part, because there was simply nothing in Europe equivalent to such a peculiar creature). However, for the small kangaroos we were seeing at Barna Mia European scientists still resorted to awkward combinations: hare-wallaby, rat-kangaroo.

Boodie (Bettongia lesueur)
In recent years there has been a tendency to drop these cumbersome Englishisms in favor of aboriginal names. The question is, how far does one take this? Should you have an individual name for each species based on a native language spoken where the animal lives (or once lived), or is it all right to use the same name for all members of a group?  Is it acceptable to use 'Brush-tailed Bettong' and 'Burrowing Bettong', or must we use 'Woylie' and 'Boodie' instead, as they do at Barna Mia?

 
Anyway, here is a video clip of Boodies, or Burrowing Bettongs, or whatever, doing their stuff.  If you want to know more about these and other Australian marsupials, and the threats facing them, you can't do better than read the book A Fragile Balance: The Extraordinary Story of Australian Marsupials by Christopher Dickman (University of Chicago Press, 2007).

So what is Barna Mia?  A nature sanctuary, a breeding centre, or a sort of open-concept zoo?  Perhaps, if this is really the only way that rare animals like these can survive in something approximating the wild, it doesn't matter. Certainly, even if Barna Mia's Bilbies, Bettongs and such are lured into view for tourists and fed by people, this is better than seeing them in a cage.  Outside the fence there may be little awaiting them but the stomach of a fox or a cat. Perhaps the best way to think of Barna Mia is as an artificial island, surrounded by still-inhospitable mainland rather than by the ocean surrounding the real islands where some of these animals, otherwise, would have their only refuge. Whatever it is I am glad it is there, and I am glad that we had a chance to see it. 

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