Sunday, 24 August 2014

Paradise Lost

Brisbane is changing. 

When people say this, they usually refer to the cosmopolitan aspirations of a city no longer content to be regarded as an overgrown country town. It is now a city that caters to an affluent, expansive and modern middle class, offering fine-dining, bars, shopping precincts and lifestyle options that rival those found in Sydney and Melbourne, perhaps for the first time in its history. But I have lived here long enough to notice other ways in which Brisbane is changing.

Rainbow Lorikeet, Bracken Ridge
When I was a young boy with a bird interest, I could study the feathered visitors to my garden and neighbourhood for hours. I especially loved the evenly-mixed flocks of Rainbow (Trichoglossus haematodus) and Scaly-breasted Lorikeets (T. chlorolepidotus) that would visit the grevilleas Mum had planted around our housing commission yard in Bracken Ridge. Today, the Rainbow Lorikeets are as numerous as ever around Brisbane's suburbs, but the Scaly-breasted 'Greenies' have disappeared for some reason, and the Pale-headed Rosellas (Platycercus adscitus) have gone with them. They are both still common birds in bushland reserves, but no longer in our gardens.

I point out subtle shifts like these because they pose the threat of becoming declines that are drastic and irreversible later on. We can't afford to be complacent or unobservant about these changes to wild Brisbane, because history tells us we should be concerned. If there's time for new restaurants, sports and party haunts, perhaps there's also time for a history lesson?


Paradise Parrot (Psephotus pulcherrimus)

Paradise Parrot; Illustration by William Cooper
To the eternal shame of South-east Queenslanders, the one bird to have been declared extinct in Australia since European settlement was found in our corner of the country only. 

The evocatively-named Paradise Parrot was never an abundant bird to begin with due to its specific habitat requirements. One of three closely-related parrots adapted to life in the tropical savanna woodlands of northern Australia, the Paradise Parrot was the southernmost representative of the group. Together with the Hooded (P. dissimilis) and endangered Golden-shouldered Parrot (P. chrysopterygius), these gorgeous birds are known colloquially as 'antbed parrots' from the way in which they excavate their nests inside termite mounds.

The two other 'antbed parrot' species currently survive only because they live in remote areas of northern Australia. The Paradise Parrot was not so lucky however, residing in a part of the country that was being drastically altered by settlers in the late 19th century. The effects of heavy, hungry and hoofed livestock on a landscape that had never endured such stress damaged the native grasslands that the Parrot relied upon for food. This, alongside a lethal combination of poorly timed burn-offs, feral predators and a series of droughts, sealed the sad fate awaiting this native beauty. By the early 1900s, it had disappeared from its former haunts around the Brisbane Valley, Darling Downs and beyond, motivating naturalists to locate the few remaining pairs. These were found in the Burnett River region, but it was too late to turn around such a severe decline for the species. The last confirmed sightings of the Paradise Parrot were of a well-studied pair near Gayndah in 1927. 


Mount Glorious Torrent Frog (Taudactylus diurnus)

Mount Glorious Torrent Frog;
Photo by Queensland Government
Brisbane residents are often very fond of the D'Aguilar Range, a series of forested summits and slopes cradling the north-western suburbs of our city. Some of my earliest nature memories take place there at the peak of Mount Glorious, in what was then known as Maiala National Park. Following the rainforest track along to Greene's Falls as a child, I never knew at the time that a former denizen of those very rockpools existed no more.

The Mount Glorious Torrent Frog was one of six related species that are unique to Queensland. All of them are known to have small and isolated distributions along just a handful of upland rainforest streams, and another one of these frogs - the Sharp-snouted Torrent Frog (Taudactylus acutirostris) - is also presumed extinct. 

When populations of animals are so small and localised, they become extremely vulnerable to disease, and it is for this reason that the Torrent Frogs are so badly afflicted by an aggressive fungal disease that is killing amphibians globally. The fungus involved is a chytrid named Batrachochytrium dendrobatidis, and is believed to have been spread by the African Clawed Frog (Xenopus laevis), a species with a natural resistance to the pathogen that has been used in science laboratories the world over since the mid-1930s. The fungus seems to have arrived in our part of the country 40 years ago, as the Mount Glorious Torrent Frog was a common species in 1970, but had been wiped out by 1979, despite living in fully protected National Parks. The rockpools of Maleny, Mount Glorious and the Conondale Ranges are still beautiful places to visit, but never again will they bear the soft chuckling call of the Torrent Frog.


Brisbane River Cod (Maccullochella species)

Early European explorers could not speak highly enough of the Brisbane River upon seeing it for the first time, describing it as a natural wonder of the Australian east coast. Deep, clear and cloaked with thick lowland rainforest, the river attracted settlers from far and wide to make full use of the bounty it was offering, which included a freshwater fish so enormous that it could feed many men with each capture. Initially so common that it was even fed to pigs, the Brisbane River Cod was greatly over-fished, and this, combined with increasing degradation of its once pristine home, led to its total disappearance by the early 1900s. The Brisbane River has since been re-stocked with the related and endangered Mary River Cod (Maccullochella mariensis). Amazingly, the once numerous Brisbane River Cod had fallen extinct before experts could examine even a single specimen, and thus it has no scientific species name.


Eastern Quoll (Dasyurus viverrinus)

Eastern Quoll; Photo by Dave Watts
Some animals that are extinct in South-east Queensland survive elsewhere. Besides the Tasmanian Devil (Sarcophilus harrisii), some of Tasmania's most remarked-upon animals are the Eastern Quolls that visitors occasionally see in the National Parks. These delightful animals (the size of a large kitten) had been found on the Australian mainland up until 1963, when the last known individual was hit by a car in the Sydney suburb of Vaucluse. The cause of their demise in Brisbane dates back earlier than this however, with predation from introduced foxes probably playing a major role alongside disease. The larger and more robust Spotted-tailed Quoll (Dasyurus maculatus) still maintains a very fragile and isolated population in Greenbank Army Reserve.


Darling Downs Hopping Mouse (Notomys mordax)

The only proof that this native mouse ever existed at all is a single skull that was collected from the Darling Downs in the 1840s. It shared its grassland habitat with the Paradise Parrot, so it too may have struggled in coping with changes brought about by the introduction of livestock.

Australia's Hopping Mice have a shocking survival record. Of the ten species known to science, half have become extinct since European settlement.


Southern Gastric-brooding Frog (Rheobatrachus silus)

Southern Gastric-brooding Frog; Photo by Mike Tyler

One of the most fabulous creatures the world has ever known was a South-east Queensland local. In 1972, a frog was discovered in Kondalilla National Park (near Maleny) that was an unusual amphibian by Australian standards, in that it was almost completely aquatic. It took another two years for the creature's most astounding secret to be revealed however, when a group of young naturalists share-housing in Red Hill made an incredible observation on a captive frog in their aquarium. You've probably figured it out from the name of this species and the accompanying photograph above, but it was discovered that the female Rheobatrachus incubated her eggs by swallowing them, keeping them protected and warm inside her stomach. Further research revealed that the developing tadpoles secreted a hormone that altered the functioning of their mother's gastric system, temporarily bringing a halt to the production of stomach acids and intestinal processes so that they could mature into tiny frogs inside. When it was time for the young to swim free into the rainforest streams of the Blackall and Conondale Ranges, the mother would regurgitate her babies, which is what was witnessed by fellow blogger Greg Roberts and his friends one night in 1974 for the first time.

Sadly, the Southern Gastric-brooding Frog shared its rainforest stream environment with the Mount Glorious Torrent Frog, and thus, a similar fate awaited it. 1979 was the year that South-east Queensland lost not one, but two unique frog species to the spread of the lethal chytrid fungus. Another Gastric-brooding Frog species was discovered in Eungella National Park near Mackay in 1984, but it too had disappeared just one year later. Some people would shrug their shoulders at the loss of a secretive and not particularly attractive frog, but these are the same people who could have potentially benefited from medical advancements made from the study of the animal. Perhaps stomach ulcers, cancers and other ailments could have been a thing of the past thanks to the unique biology of this species. Instead, it is the frog that is resigned to history. 


Coxen's Fig-Parrot (Cyclopsitta diophthalma coxeni)

With advancements in DNA and genetic studies being made every year, the classification and status of animal species undergoes frequent change. What seems to be the trend is that animals that have been previously thought of as wide-ranging and common are now often revealed to be a collection of similar-looking but genetically different species. Such findings can be cause for alarm - for example, when Victoria's Burrunan Dolphin (Tursiops australis) was revealed to be a genetically distinct species from the almost identical-looking Bottlenose Dolphin (Tursiops truncatus), they could no longer be counted as part of the 600,000 individuals found worldwide of the latter species. Suddenly, they were just a population of 150 animals, found in two pods in Port Phillip Bay and the Gippsland Lakes.


Coxen's Fig Parrot; Illustration by Katherine Castle
Possibly a similar revision may take place in the future with the Double-eyed Fig-Parrot (Cyclopsitta diophthalma). There are eight different races or subspecies of this tiny rainforest parrot, with five in New Guinea and three more along the Queensland coast. The southernmost race, referred to as Coxen's Fig-Parrot, is found in South-east Queensland and Northern New South Wales, but it is on the verge of extinction thanks to the clearing of its former lowland rainforest home. DNA analysis of this bird has never been undertaken because no genetic material from it has ever been secured - not even a single feather or egg. Should the opportunity arise in the future and it be given full species status, its estimated population would be fewer than 250 birds.

Even this population estimate is contentious though. Some South-east Queensland birdwatchers feel or fear that the bird is much closer to extinction than that, or that it may have already disappeared altogether. A lack of publicised sightings for many years, coupled with the fact that a Coxen's Fig-Parrot has never even been photographed, gives weight to these concerns. Another explanation however, is that sightings of this Parrot are suppressed by authorities, so as not to place undue stress on populations from black-market poachers and hoards of amateur photographers - lets not forget Yellow Bittern hysteria! 

If you want to play a part in the survival of this species, there are a few things you can do. Keep an eye out for Fig-Parrots when visiting hinterland locations like the Conondale Ranges or Lamington National Park. They are the smallest Australian parrot, with body proportions similar to the African lovebirds that people keep as pets. Pay particular attention to fruiting fig trees, even if they are isolated specimens on farmland or outer suburbs, as the Fig-Parrots are nomadic. Pieces of fig-flesh falling from the trees can indicate the presence of this bird, as they feed on the seed inside and discard the fruity casing. Be sure not to confuse them with the common Little Lorikeet (Glossopsitta pusilla) either - Fig-Parrots don't frequent eucalypt trees the way this species does. Report any Fig-Parrot sightings to Ian Gynther, who is the Senior Conservation Officer at the Queensland Department of Environment and Heritage Protection (ian.gynther@ehp.qld.gov.au). Lastly, if you live on a rural property or are blessed to have a large backyard, consider planting one of the Parrot's local food trees, such as the Moreton Bay Fig (Ficus macrophylla), but situate this rainforest titan away from fences, pavements and buildings! With your help, the Coxen's Fig-Parrot just might live to see the dawn of a new day.

Sunrise over Beerburrum State Forest, D'Aguilar.

4 comments:

  1. Interesting read Christian.It is important to notice trends, they are natures warning bells. We have noticed a drop in Fairy-wrens, both Red-backed and Variegated over the last two years. This drop has occurred at the same time as a new bird in our area has arrived: the Common Myna, and there has been some subtle habitat degradation as well. Over the last four years we noticed the absence of Scaly-breasted Lorikeets but this year we were delighted to see them back again and in good numbers too.

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    1. Thanks Sri. I suspect the Common Myna is behind the changes in Lorikeet abundance too, as they are aggressive hollow-nesters and only the Rainbow Lorikeets are bold enough to stand up to them. I should pay closer attention to the RB and V Fairy-wrens, but I have noticed the Superb Fairy-wrens move into Brisbane over the past two decades - John Noyce's book 'Birds of Redcliffe, Pine Rivers and Caboolture' from the mid-90s lists them as uncommon at the time!

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  2. The usual informative and expert read from you Christian. I hope that your blog is widely read both where you live and further afield because as you rightly say, Brisbane (and so many other places in the world are underdgoing both subtle and major changes which are not understood by enough people.

    I am in the process of reading through the latest book about the Passenger Pigeon,a cautionary tale if ever there was one. More strength to your typing my friend.

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    1. That is very kind praise from you, Phil. Thank you!

      The story of the Passenger Pigeon has always fascinated me! On Sept 1st, it's actually the 100th anniversary of the passing of 'Martha', the last Passenger Pigeon on Earth. Will have to hunt a book or two down to read more.

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