The Wildlife of the World’s Deserts – Part 2 – Australia

Uluru and Australia’s Red Centre

Above the Crest-tailed Mulgara

Uluru, also known as Ayers Rock, is world-famous for its startling red colour and is regarded as one of the great natural wonders. It is situated in the centre of Australia, in the southern part of the county’s Northern Territory and at the far-eastern end of the Great Sandy Desert. Uluru is the biggest single piece of rock in the world; it is made of arkose sandstone, and its height is 348 metres. What is visible is in fact just a summit of a much larger piece of rock, with most of its bulk lying underground, possibly to a depth of several kilometres. Urulu is a relic from the process of major mountain formations that have been eroded over millions of years.

Urulu holds special significance to local Aborigines, not just as a rock but as a mysterious personality, and caves around the base of it contain hundreds of paintings depicting traditional Aboriginal life. Urulu is also famous for the changing colours and light patterns that dance across its intense rust-coloured form. A few weeks ago it was announced that climbing onto the rock was no longer allowed on request from the Aborigines’ leader as they continue to regard Urulu as central to their spiritual life.

The Sandy Desert surrounding the rock covers 405,200 square kilometres and extends west from Urulu into the state of Western Australia. The landscape compromises extensive sand plains, with sand dune fields, from which rise rocky outcrops. Rainfall is minimal but rising to 300 millimetres around Urulu. There are a few permanent water sources and they are located around the periphery of the desert. The average temperature in the daytime is 22 degrees Celsius rising to 45 degrees Celsius in summer, and dropping in winter to almost freezing point.

Urulu is a defining symbol of the desert and an excellent place to search for wildlife. Tussock grassland is dominated by species such as Spinifex. Large parts of the desert are covered by clumps of Spinifex, a most drought-resilient plant that provides a valuable habitat for small birds in particular. The tussock vast root system enables the plants to obtain moisture from the soil and stabilises the sand dunes on which they grow. Scattered throughout the desert are shrubs and small trees like Desert Walnut, Mulga Acacia, Desert Bloodwood and Desert Oak.

The wildlife around Urulu is particularly diverse due to the microclimate that is generated by the rock itself. Rainfall locally is higher than in the wider desert beyond and the area around Urulu has recorded 21 species of native mammals, 178 species of bird, 72 species of reptile, and many thousands of insects.

One of the most remarkable reptiles found in the Red Centre is the Thorny Devil. They are extraordinary looking lizards that can grow to 20 centimetres long and have a body pattern that provides excellent camouflage against the sand of the desert. It moves along in a jerky motion like a wind-up toy and with its tail raised. The lizard’s body is covered with spikes to deter predators, although they are not poisonous. This creature’s bizarre appearance is not its most remarkable aspect. In an adaptation that is hard to believe, it is able to channel any moisture that collects on its body, from dew, towards its head via a system of external capillaries and tiny grooves between its spines. This network leads to its mouth enabling it to drink. It is one of the examples of the ingenuity of nature when presented with a challenging environment.

Another notable creature is Main’s Frog which endures periods of drought by burying itself underground and surviving on the water that it has absorbed into its body in time of rain. When the rain comes back, the frog digs himself out, feeds, reproduces and then stocks up on its water reserves before going underground once more. At times of heavy rain, hundreds of frogs may emerge simultaneously making a strange call rather like the bleating of a particular farm animal – hence their alternative English name, Sheep Frog.

The Great Sandy Desert is home to many mammals, among them Dingo Dogs, Red Kangaroo and Hopping Mouse. In the 19th century, camels were brought to Australia. With the development of the motor industry, they become unwanted and pushed out into the desert where they thrived.  With over a million feral camels grazing on vegetation that is used by the farmers and their cattle it became a serious problem. The government intended to cull at least 650,000 of them but met with the opposition from many naturalists who maintain that would be cruel.

I should mention the many snakes that slither across Australian deserts and the landscape, such as Australian brown snake, Taipan, Red-bellied black snake, Spotted python, Tiger snake, Mulga snake, Desert death adder, Eastern brown snake, but by now I feel somewhat queasy and so I better stop the count. Needless to say, most are highly venomous. The Eastern brown snake is the most aggressive one and is responsible for more deaths in Australia than any other snakes. Its bite will kill within 45 minutes and the description of what and when gets paralysed is the stuff of nightmares. I hope readers will understand why I won’t be including pictures of any of the reptiles. By coincidence, yesterday’s newspapers featured a tragic incident in Australia. A British backpacker, aged 23, working on a prawn trawler became the country’s second victim to die from a sea snake bite. He was bitten on a finger by a sea snake caught in the net. When he asked the first mate: ‘Will I be all right?’, he was assured that he would be.  Within a short time, he lost consciousness and died shortly after. At an inquest, his mother said: ‘My son had been living the dream before he was robbed of his future.’ The inquest continues. I rest my case.

As an antidote to the horror above, I would like to include a picture of a symbol of Australia – the koala. Although not a desert dweller, the koala is of great importance, especially now, since its numbers were significantly reduced by the still-burning bush wildfires.

There are quite a few deserts in Australia and the Great Sandy Desert is the second largest covering 267,250 square kilometres. It wouldn’t be possible to write about all of them in this post and therefore I will write about the most interesting one after Urulu:

The Simpson Desert and the Inland Sea of Lake Eyre

It covers some 580,000 square kilometres and has a range of different arid landscapes, from dune fields and stony plains to low eroded low hills. Lake Eyre is the world’s largest salt lake, and at some 15 metres below sea level, the lowest point in Australia. It also includes one of the world’s largest internal drainage basins. Regarded as one of Australia’s great natural desert features, the lake is fed largely by water from the Warburton River. There is no outlet to the sea and so the basin fills with the seasonal rainwater, followed by rapid evaporation. This results in the formation of salt pans that are for much of the time covered by a crust of salt that can be half a metre thick but after the monsoon rain, the lake water can swell to a depth of two metres or more. However, this results in the salt crust dissolving and raising the salt level in the lake’s water to saturation point. The heavy salty water sinks under the fresh and drinkable water that comes to the surface. The resulting flooding transforms the arid, parched and lifeless parts of the surrounding desert into a vibrantly green, full of life landscape. The desert erupts in colourful displays of brilliantly yellow flowers, Fleshy Groundsel, but the extent of the growth of the grasses and shrubs depends on local rainfall.

The wildlife of the Australian deserts includes the most popular and cute mammal, Bilby. It lives singly or in pairs, is nocturnal, and feeds on insects, seeds and bulbs. Once widespread, it has now declined in numbers which prompted a conservation campaign, including captive breeding. There is even a National Bilby Day which is held every September.

Australia’s ‘wild dog’, Dingo is present in the Simpson Desert in larger numbers. Its history is curious as it is likely that it was brought to Australia as a domestic animal by Asian seafarers. The earliest surviving fossil remains for Dingos are most likely from Thailand, dating back almost 6,000 years. This would indicate an original and close link with the Indian Wolf, although Dingos are now regarded as feral dogs. Aborigines developed an early relationship with Dingos, using them as guards dogs and in hunting. Dingos hunt in small groups, preying on kangaroos and wallabies.

Outstanding among the many reptiles found in the Simpson Desert is the highly specialised Lake Eyre Dragon. A small creature, about 7 cm long, it lives only on the inhospitable salt flats where it feeds on ants. To avoid the heat it burrows under the salt crust and when the lake periodically floods, the dragon will move temporarily toward the sandy shores until waters recede, and then moves back to the salt flats. To cope with the extremely harsh conditions, the Lake Eyre Dragon developed a pale skin to reflect the heat and its sunken eyes have black-rimmed fringed lids to cope with wind and glare.

Over 239 species of birds have been recorded locally which is a surprisingly high number for a desert region. The lake attracts many waterbirds, among them Pink-eared Duck, Grey Teal, Red-necked Avocet and Black Cormorant. The Red-necked Avocet comes to the Lake Eyre in large numbers when conditions are favourable to breed and it feeds on tiny organisms  which it scoops up with sideways sweeps of its long bill

When the water levels are right, a vast number s of pelicans gather at Lake Eyre to nest. They fly from hundreds of kilometres away to take advantage of the temporary conditions inland. When not feeding they spend long periods resting and preening.

This is just a small selection of the diverse and large wildlife population of the Simpson Desert and Lake Eyre. Conservation efforts are helping in preserving this natural wonder forevermore.