The “Respect the Mountain” forum ( here, here, and here ) at the Hobart Town Hall earlier this year prompted Don Knowler to return to a diary he compiled after daily rambles on Mt Wellington during the previous year. In what promises to be a momentous year in the modern history of Kunanyi, the weekly diary gives the mountain and its wildlife its own voice. All Don’s Mother Mountain columns – and much more by this superb writer – can be found under the Category, Don Knowler, here
Clambering across rocks just below the Organ Pipes I slipped heavily on loose boulders and took a tumble. I rolled a couple of times, reaching out desperately to grab something that would stop my fall. I had dislodged a small fragment of dolerite rock and as I sat there, a little shaken, I realised it was still clutched in my hand.
Just a little piece of rock, of little significance in the greater scheme of things on the mountain. All the same I sat there studying the fragment, thanking it for stopping my fall.
I’d never studied dolerite close-up before and I could see it was a work of art, as stunning and magnificent as the sandstone I am familiar with on the lower slopes, and on the ancient, Georgian buildings on some of Hobart’s smarter streets.
Some of the buildings are constructed of dolerite, too, but those always appear dull and uninspiring, especially when set against the smooth, carved and polished sandstone.
This dolerite fragment sparkled in my hand, the grains of crystal embedded in it shining like glass, catching the sun’s rays and throwing them back into my face. There were different shades of grey, meandering in layered seams across the fragment’s surface.
The rock was fresh and shiny new, fresh out of the box, and it slowly dawned on me that it would have been the first sunlight this rock had seen in 170 million years. I felt privileged to be in at its rebirth, feeling at the same time a little insignificant. A little insignificant, I might add, is something of an understatement.
The dolerite columns that make up such significant features on the mountain as the Organ Pipes and Cathedral Rock, along with the Potato Fields carpet of scree, are the new kids on the block when it comes to Mount Wellington’s geology.
The molten magna thrusting through the earth’s surface and cooling to eventually form the stand-out features was the last addition to the peak’s complex geology.
Sedimentary rocks of the Permian Period, dating back 230-280 million years, form most of the foothills around Fern Tree in the south, South Hobart and Lenah Valley to the north. Creamy white to grey in colour, these mudstones and sandstones are visible in horizontal or gently dipping layers. Marine fossils can be found in places. Triassic sedimentary rocks (180-230 million years) occur above the Permian, at about the 600-metre level. These comprise thickly-bedded quartz-rich sandstone and shaly mudstone, forming the cliffs and promontories around The Springs, Rocky Whelan’s Cave and Sphinx Rock.
If the mountain’s rock structure is not obvious, hidden under tree and bush, the forests will inform you. Black peppermint gums favour sandstone soils and these beautiful trees – with smooth grey bark like an elephant’s hide and narrow, long leaves – provide a geology lesson of their own. Find black peppermint and you will find sandstone.
White peppermint gums, also fine-leaved eucalypts but with a smooth trunk infused with streaks of grey, yellow and ochre, favour dolerite rock and soils. They point to the latest geological event, when the igneous rock intruded during the Jurassic Period. Shrinkage cracks developed while the molten magma cooled, forming large vertical columns, the Organ Pipes being the best example.
A third species of peppermint, the silver peppermint, is recognised by its bluish-grey foliage and favours foundations of mudstone.
The far-carrying and repetitive cry of the spotted pardalote forms the background sound of the mountain, as vital and omnipotent as the wind rustling leaves, the trickle of water on the smallest of watercourses splashing over rocks.
It’s so familiar I don’t often hear it, my mind filters it out, instructing the senses to scan for the unusual or irregular. So I see the pardalotes more often than I am aware of hearing them. Tiny but plump shapes flit in front of me, and I always know it’s them, blunt shapes with an equally blunt bill. The pardalotes travel short distances in undulating but fast flight, seeming to fly full-throttle into the upper branches of eucalypts, then sticking to clusters of leaves like glue.
Close-up they are stunningly beautiful birds, mixing red and yellows, black, white and browns. White spots speckle the plumage, given them another name: diamond birds.
In mid-August I always pay extra attention to the diamond birds and consciously listen for their two-note whistle. Another pardalote is found on the mountain, the striated pardalote which travels across Bass Strait from the mainland and in my experience is the first of the summer migrants to arrive.
I look and listen for the striated pardalotes and I grow excited: I know the first of the travellers are on their way.
August 15: cold, a southerly wind blowing freezing air off the Southern Ocean, perhaps from as far south as Antarctica. The migrants will have been stopped in their tracks but there is solace in a sheltered glen close to O’Gradys Falls. A Bassian thrush is singing a territorial song for the first time.
The green rosella gently picking at the seeds of a yellow bottlebrush carried a stature and grace about it that told of a long life well lived.
During my travels on the mountain I had learned that the brighter the colours of a rosella, the older the bird and the bright colour of this old fella – especially the bright yellow on the breast and underbelly and iridescent blue in the wings – certainly suggested he had reached an age that in humans is marked by retirement.
Measured in human terms, in the way we talk of dog years, the life expectancy of a rosella at 15 to 20 years must be the equivalent of between 60 and 65 human years.
On a chilly day, watching a green rosella in the autumn of its years can put the life of a person who has reached retirement age into a different sort of perspective. It’s a good time to contemplate our own lives, and to consider the age-old question of what separates humans from what was termed the “brute creation” in not so distant times.
One thing that certainly separates us and the rest of nature is that birds and animals don’t get to retire, and in turn to contemplate a fundamental change in existence.
The green rosella’s fate, when it is too old to fossick and fly, is to wrap itself in its wings one cold night and slip quietly to that happy hunting ground of native cherry and bottlebrush seed in the sky or, more grimly, to have his slower movements in the trees betray it to the sharp talons of the marauding brown goshawk.
As a “baby-boomer” retiring just over a year previously I was warned by my doctor to prepare myself for the upheaval of leaving the workforce and the social life that went with it, especially the camaraderie and mateship of a lifetime spent as a journalist.
And friends in the medical profession said that retirees often faced depression, feeling they were no longer constructive members of society. They felt like outsiders, isolated, out on a limb.
My friends were worried that the energy I devoted to my bird column, and walking on the mountain and in the woods to gather research, might not be enough to keep me occupied. Even though I pointed out that bird-watching was an ideal pursuit for the retired – keeping people fit and alert – it was suggested I join a men’s shed for companionship, or some other group to keep me involved and active.
On that score I’d been lucky to have discovered the Hobart City Council’s Bush Adventures program and this had provided a vital contact with new faces and a wider interest in nature to go with my birding. Whether it be studying flowers, trees, fungi, birds or even bats, I found people who shared my interest.
My first outing of the nature’s new year was billed a Pinnacle Discovery Walk to study nature in the alpine zone on Mt Wellington. I had needed a lift of spirits on the snow-covered mountain that morning because I was feeling a little down. I had found the bright yellow feathers of the old rosella on my lawn, the old boy no doubt falling victim to a predator during the early morning as the sun came up.
