By MIKE GILLAM
All photographs © Mike Gillam
Instead of true leaves Acacias have phyllodes and dead finish, Acacia tetragonyphylla, has one of the narrowest, sharpest phyllodes of all.
The scientific name describes the phyllodes well. Acacia is derived from the Greek Akakia, meaning sharp point, tetra (four), gonia (angle), phullo (leaflet). Accordingly, dead finish is an Acacia with four-angled-leaflets.
The distinctive lipid rich yellow aril attached to each seed is prized by birds and ants that carry the seed away from the parent plant and thereby aid its dispersal. Birds are attracted to Acacias with red and yellow arils, while ants favour smaller seeds with white arils but will also take those with yellow and red.
The name ‘dead finish’ describes this plant as one of the hardiest drought survivors and when it dies, that’s the finish of all plants or so the story goes. Certainly during extended drought this Acacia sheds many of its pointy phyllodes and although it can resemble a dead stick, ‘lifeless plants’ can quickly spring back after rain.
Perhaps the greatest admirer of dead finish is the zebra finch, Nyingke, a name sometimes abbreviated to Nyi Nyi, by fluent and charitable Arrernte speakers trying to help illiterates like me.
For the Arrernte, Arlketyerre is highly valued as both food and medicine. The seeds are usually ground into a paste and cooked in the coals while the spiny phyllodes are used to treat warts. In similar fashion to witchetty bush, edible larvae are collected from the plants’ roots.
I’ve written before about spending long hours in the company of Nyi Nyi, watching them arrive at a rock-hole, cautiously moving from favourite sunning perch amongst the spear-bush to the deeper shade and protective cover of a native fig; then the final dash to water to bathe and drink.
From memory on the day I took this photograph, the temperature was about 38 C and I’m fairly confident it was the same flock of finches returning to drink every twenty minutes. Each wave of birds left the safety of the fig, pausing to drink for just a few seconds before returning, whereupon the next wave would repeat the process. I’m certain some went back for seconds and possibly thirds.
The flock of several hundred socialised and loitered in the deep shade. The thousands of white dots of urea on the rocks under the fig are a testament to six months without rain. Their water balance restored, the flock departed the gorge heading in the direction of their feeding and nesting grounds where dead finish dominates the inter-zone between low hills and the nearby watercourse.
The spiny dead finish, Acacia tetragonyphylla, is vitally important for nesting finches and key shrubs can support large colonies where survival of offspring is reputedly higher compared with more dispersed sites.
While dense foliage and spines afford some protection, pygmy goannas, snakes and predatory birds still push through to feed on both eggs and hatchlings. Yet, with only 14 days of incubation and a further three weeks before finch fledglings leave the nest, rates of survival are high.
Finch food favourites includes native millett, Panicum decompositum, and wooly oat grass, Enneapogon polyphyllus. On several occasions I’ve watched athletic male finches leaping up to grip the wooly oat stem in their beak and using their weight to pull it down so a female can feed on the seed head.
Two Alice Springs researchers recorded finches eating wooly oat grass and purple plume grass, Triraphis mollis, and introduced buffel. Their ‘cafeteria’ trials* exposing captive finches to various seeds did indicate a preference for native grasses. Nyi Nyi are also known to eat insects such as termite alates especially when they’re rearing young.
Most human inhabitants of Centralia recognise the strong bond between Nyi Nyi and water. They are the ultimate water diviners of the desert and stories abound of finches leading thirsty travellers to water. A few lucky locals are graced by the presence of finches in suburbia, more so in the outlying rural areas, where the Nyi Nyi choose a garden pond or bird bath with all the right qualities.
Answering the call of the Nyi Nyi
Not long after settling in old Eastside, a leafy suburb overlying the original coolibah floodplain, we heard the Nyi Nyi calling out during a flyover. Our house was situated just below Winnecke Avenue, an elevated road delineating the ancient levee of the Todd River floodplain. The barren rocky outcrop flanking the eastern side of the road, was doubtless a stronghold of dead finish and witchetty bush before European settlement.
The distinctive outcrop of Tjoritja (Spencer’s Hill), an important rock wallaby refuge, lies two hundred metres to the north. From the roof of our house we could see the canopies of the river red gums in the normally dry sandy channel that defines the western boundary of the suburb.
Built over rich alluvial soils, old Eastside is flood prone. The suburb is rescued from botanical irrelevance by the unifying presence of occasional majestic river gums, coolibahs and ghost gums, mostly remnant survivors but also others that were planted by early colonists.
Answering the call of the Nyi Nyi, I enthusiastically placed containers of fresh water in the most visible points of the garden. I changed the water daily for several weeks and apart from white plumed honeyeaters and crested pigeons, my rock-holes were shunned.
I reasoned that the welcoming perching trees were pretty ordinary in a citrus kind of way and arranged some spectacular dead branches overhanging the pools. No positive effect.
Clearly, the Nyi Nyi didn’t think the yard was worth a second glance as they flew between the nesting and feeding sites surrounding Tjoritja and the river. It was early days and there was much to do in our quest to return a sense of wildness to our impoverished suburban block.
We removed the couch grass carpet, replacing the billiard table green with a barrier layer of thick cardboard to curb regrowth and then spread a generous layer of mulch on top. The babblers visited within days boosting our morale and along with others displaced by the old European order, they became a permanent and delightful presence.
We planted an array of wonderful endemic plants including Callitris pine, mulga and dead finish. Undeterred by the finch’s rejection of our desert paradise we kept planting endemics and eradicating introduced weeds, especially the determined couch grass that crawled under our neighbours’ fences.
The following year I collected a huge amount of what I believed was Nyi’s Nyi’s favourite seed, native millet, Panicum decompositum, and this was irrigated with the grey water system we’d installed to recycle our shower water. The grasses grew quickly and soon we had a clump of about six square metres.
Growing waist high the backlit grasses with their delicate sprays of seeding heads were exquisite but not a chirp of commendation from the Nyi Nyi. I knew this was the most fabulous clump of Panicum in perhaps 100 square kilometres. Surely the next generation of finches or the next would deviate from slavishly following those flyways established by their parents.
Mine was wishful thinking because year after year the Nyi Nyi failed to visit. I briefly entertained the thought of a really big surface of water but other obsessions took over. I think I was defeated by the botanical pizza that even leafy old Eastside presented to many birds flying overhead.
Notwithstanding the omnipresent river corridors and pockets of remnant bush-land, suburbia offers a state of confusion, of contrasting, colliding and fragmented garden themes. We can only imagine the visual chaos and ecological discord this offers to urban wildlife generally.
Other birds did find our garden and avian activity soared over the five years we lived in the street but we didn’t enjoy success with the elusive Nyi Nyi until we relocated to Hele Crescent. It was a lesson in location, scale and a lucky rainfall event.
Here in the protective embrace of nearby Teppa Hill we noticed several pairs of finches nesting in a mature dead finish on our back boundary. The finch numbers seemed tenuous and we quickly organised fresh rainwater daily, in places that made life difficult for cats to lie in ambush. Then we began trapping the cats.
The Nyi Nyi thrived. We removed weeds from the site and planted in ways that enhanced the nearby bush, or more accurately our imaginings of that bush before the reductionist era of buffel grass. Still, here and there, in obscure little pockets some of the natural order miraculously persisted.
Wherever we found a native plant struggling we removed the surrounding buffel and the endemic survivor always expanded in appreciation, producing flowers and more seed.
We took our cue from the nearby hills and a belief that working with the country was key to success, and Teppa Hill provided a cascade of free plants with every downpour and modest flow from the catchment above.
The ratio of buffel seedlings to endemics was probably 100:1 but we were dogged and uncompromising in our vision for the site. Gradually the seeds of the finch favourite wooly oat grass, Enneapogon polyphyllus, and many other fabulous grasses colonised the rich colluvial soil. Native herbage such as ruby saltbush triumphed where we removed buffel and several species of mulla mulla / pussy tails, Ptilotus, got a foothold on the flanks of the hill where we removed rosy dock.
Over time the Nyi Nyi invaded new building structures, air conditioner stands and showed immense approval of artist Dan Murphy’s use of bed springs in his sculptures. Inexplicably they ignored our multiplying dead finish. Nesting pairs increased most years and now after two decades we have a vigorous population of finches numbering from a low of 20 in the drought years and a peak of about 50 after optimal rain.
Much has been written about this amazing finch, notably its rapid breeding response to rainfall events, communal nesting behaviour, diet and of course that endearing voice, more highly developed in males.
There are certain quintessential sounds of Centralia including bird songs that connect us all to this place. High on the list would be the joyful sound of Nyi Nyi, alongside the signature call of the whistling kite, raucous mimicry of bower birds, mellifluous song of the butcher bird and the aargaaargaargaaa of baby galahs begging for food. I hear some of these sounds every day and I can’t imagine living without them.
I could go on and on and on: the music of dove and pigeon wings or the more delicate whirr of Bourke parrots arriving at a remote waterhole in the predawn. The sound of ten thousand budgerigars changing direction, a decelerating and resonating whirr like a giant flying fan, spinning out of control. I could keep on, as well you know, but I’m trying to show restraint while probing my own connections to this extraordinary place.
Obviously we could all give up these aural familiars, or could we? Artist friends with equally deep connections to the desert have retired from Centralia and ‘gone south’ to live near the ocean! Perhaps they will find new sounds to lift their spirits and soothe the heart-ache or, more likely, they’ll be back to visit the Nyi Nyi.
* Zebra Finches forage on seed from invasive Buffel Grass, but prefer seed from two common native grasses by Lauren I. Young & Christine A. Schlesinger, Emu – Austral Ornithology, Volume 118, 2018 – Issue 4.