Fabulous Flinders Ranges
Thursday November 22, 2012
[From the trip Fabulous Flinders Ranges]
The Flinders Ranges are located some 600 km N of Adelaide (SA). The land is a country of thick, gnarled gum trees, growing alongside stony creeks. There are ruins of farms left by pioneers, beaten back by the harsh landscape. The Flinders Ranges is an ancient and unique part of the world, and consists of a series of impressive ranges of steep hills and soaring rock formations on the edge of Australia’s outback. Dry creekbeds can flow any time following rain and flash flooding is common. Narrow, deep gorges cut into geological layers that date back 800 million years.
We entered the Flinders Ranges from the north, on a spectacular road that rises steeply from the barren, stony gibber-plain near Parachilna (from where you can almost see the curvature of the earth). At the start of the Geological Trail, appropriately named A Corridor Through Time, we read about the fascinating history of the mountain ranges.
From between 800 and 500 million years ago the sea flooded an immense trough which had been created by movement and sagging in the earth’s crust.
Over time, huge amounts of rock, silt and sand eroded from ancient highlands in the west and north-east washed into the subsiding trough. By 500 million years ago the layers of accumulated sediments had been crunched and compacted into bands of rock up to 15 km deep. More movements deep in the earth’s crust then shunted these layers into folded mountains, before they too were ravaged by the elements, with masses of material stripped from towering peaks to expose a battered backbone of ridges and rocky remnants, which have been preserved to the day of today.
Driving along the 30 km long Geological Trail through Brachina Gorge we eyeballed a sequence of rock formations 9 km thick and spanning 150 million years. Evidence of the region’s oceanic history is scattered throughout the ranges in sandstone slabs embossed with the unmistakable corrugations of a tidal shoreline. Even more telling are the imprints of distant ancestors – yours and mine.
While all very interesting, the real attraction in the Brachina gorge for us was the Grey-fronted Honeyeater. At the fossil site of the Ediacaran fauna, tiny sea creatures that lived just prior to the great explosion of multicellular life at the beginning of the Cambrian period, we spot a pair of birds. Careful identification is required as they could of course be the much commoner White-plumed Honeyeater. We're in luck: first two, then two more, Grey-fronted Honeyeaters come down to drink from a small puddle. Suddenly, there's great commotion amongst the other birds present - largely Yellow-throated Miners and Tree Martins. We're stunned to see a Peregrine Falcon race down at breakneck speed, grab a Yellow-throated Miner and without stopping continue its flight up towards the cragged rock fromations, no doubt to its nest. Amazing!
We continue our slow drive through the Brachina Gorge. The track essentially follows the creek bed, and gets frequently washed away. The September 2010 floods had the track closed for weeks, and during our tour that year we had to walk 45 mins each way to see the Yellow-footed Rock-wallabies!
Our next stop is a colony of these beautiful but endangered creatures. Mobs of yellow-footed rock-wallabies 50 and 60 strong were regularly spotted during the 1850s. But after decades of being hunted for their skins and stiff competition from feral pests, particularly goats who ate all the ground cover vegetation, in the 199s their future was at risk. Following public pressure, the National Park finally commenced a feral animal control program, appropriately named ‘Bounceback’. After an initial number of rounds of helicopter-based goat control, followed up by ground support crew, to date the program has eradicated more than 100,000 goats out of the Flinders.
As a result, yellow-footed rock-wallaby numbers bounced back. Beautifully marked and coy by nature, they’re a marvel in motion, bopping across their cliff-face hideouts. The steadfast work of Bounceback has seen an estimated sevenfold increase in their numbers in Flinders Ranges National Park alone.
It didn’t take us long to spot a small family group of four Yellow-footed Rock-wallabies lazily resting in the shade of one of the many native Callitris pine trees. As we watched them over a cup of coffee, they showed their beautifully marked flanks, their banded tail, and their amazing rock-hopping antics.
In the previous year we had seen the rare Little Woodswallow at this site, possibly the southern-most sighting in South Australia. Today, we were treated with great views of Dusky Woodswallow, playing in the air currents amongst the cragged peaks. We also heard and later saw an Inland Thornbill, which showed its stripy chest well and down in the valley below we heard more Grey-fronted Honeyeaters calling. Two Australian Ringnecks came flying in. In SA we have two races, at times considered separate species: the Mallee and the Port Lincoln race. Here the Flinders Ranges these races intergrade showing features of both, providing evidence that these birds are one species with a number of races.
We continued on through the gorge and stopped at a broad rock-strewn riverbed surrounded by ancient, gnarled gum trees. Every time these creeks flow, which may only be once or twice a year, water soaks into underlying sediments from where these River Red Gums subsequently are supported. The gum trees contain many hollows and soon we found ourselves watching a known Elegant Parrot nest. After quite some time, an adult turned up at the nest, and young birds could be heard inside. The adult disappeared inside, probably to feed them. Another adult appeared, and the first bird emerged from the hollow. For a brief moment the pair sat on a branch together, then they flew off.
We stopped for lunch in the quaint and characteristic Wild Lime café in Blinman. Located at an altitude of 614m, this is the highest township in South Australia. We were welcomed by Sandra from Germany who recently bought the café and gave us an interesting overview of life in this isolated place, with a population of 20 souls. To the delight of our tour participants her husband brought out a young kangaroo that they were hand-rearing after its mother had died on the road. Even better, a pair of Mistletoebirds were foraging in the pepper tree shading the verandah.
We were fortunate that the weather, which had been very hot in preceding days, was quite reasonable: calm, sunny and around 30o C. After lunch we set off to search the spinifex-grass covered slopes for the elusive Short-tailed Grasswren,
The Short-tailed Grasswren was recently split from the Striated Grasswren and is one of SA's endemics. Confined to the Flinders and Gawler Ranges, the birds are shy and secretive and only found in spinifex-covered hills. The birds are slightly smaller and greyer than Striated Grasswren, with a slightly shorter tail. Their main call is a very high pitched 'seep', inaudible to some observers. During the high rainfall years of 2010 and 2011, their numbers had increased substantially. However as the area had not experienced any rain since February this year, a spectacular crash in Grasswren numbers had followed. In addition, increased numbers of feral cats and foxes no doubt played a role in this reduction. Most birders searching the slopes over the past few months had failed to find them. On our last tour we’d failed to find them for the first time ever. The prospects weren’t looking good. But we set off with a positive approach and if we didn’t’ see any grasswrens, at least there were plenty of Red, Western Grey and Euro Kangaroos to look at, as well as the odd Wedge-tailed Eagle soaring past at eye-level!
Suddenly a faint squeeking sound was heard. Could this be a grasswren? We slowly approached the clumps of spinifex from where the sound appeared to be coming and there it was! A Short-tailed Grasswren hopped out some 20 metres ahead of us and perched on top of a rock. The following 10 minutes we had multiple sightings of two birds as they foraged between the spinifex, popped on rocks to look around for danger, and at one time one bird even sang, perched on a spinifex clump.
It was an elated group of observers that returned to the vehicles that afternoon. We had an improvised celebratory afternoon tea in the shade of some beautiful white-stemmed gum trees, in which Yellow-rumped Paradalotes could be heard twinkling, and headed to our destination for the night: Wilpena Pound Resort. Picturesquely located near the National Park Visitor Centre, with kangaroos and emus at its doorstep, some of the tour participants decided to wear off the dust and heat of the last few days by a refreshing jump in the swimming pool, while others explored the surrounding bush. A great end to a great day!