While catastrophic fires eradicate habitats, it's important to think of ways to integrate nature into our city environments, writes Dr Peter Fisher.
LATE LAST MONTH, Melburnians awoke to the news that their plane trees were facing a death warrant — the city council was planning to euthanise their like in the CBD. They were causing allergenic responses from shedding leaf and shoot hairs, guilty for those sneezes, wheezes and streaming eyes despite expert opinion to the contrary.
How did we get to this overtly anthropocentric position? It's a sort of halfway house where greenery/trees are promoted as serving human needs like mitigating heat island effects, calming the psyche (amenity/liveability) but little to show by the way of specifics as to how this public intervention might influence different strands of urban wildlife and birds in particular.
Well, we’re only now beginning to peel back the layers as to the complexities of rewilding, including the Darwinian ramifications where new species look to be evolving.
Who would have thought that rainbow lorikeets might be on that path, having fastened upon a seasonal delicacy, poplar buds (carbohydrate sugars), for sustenance? The same goes for yellow-tailed black cockatoos in going for pine cones (which may have prevented the bird from going extinct).
Another place right in our midst
In any event, take a moment this spring to look up, look out, look down and above all, listen — the 'burbs are abuzz with avifaunae. The economy might be going south, but our feathered friends have lightened up.
Out in Melbourne’s Glen Eira, bird watchers have been hitting on red wattlebirds, silvereyes, white-plumed honeyeaters, crested doves, spotted pardalotes and Australian kestrels. And across many localities, there’s a biophilic sound bite of chirping rosellas, screeching flocks of lorikeets and sulphur-crested cockatoos and, if you’re in luck, the haunting “kee-yow” of yellow-tailed black cockatoos.
So, what to make of declarations of the kind that people are at the heart of cities?
A legacy of cohabitation
As far as Melbourne is concerned, it has the feel of a species turned in on itself, oblivious to the wild cohabitants and, in particular, birds. It was, after all, their original gig along with the Boonwurrung and the Wadawurrung.
Here’s how an early settler, William Westgarth, with field naturalist inclinations feted the avian delights in 1840:
I have spoken of the little bell bird, which, piping its pretty monotone, flitted in those earlier years amongst the acacias on the banks of the Yarra close to Melbourne, but which has taken its departure to far distances many a year ago. The gorgeous black cockatoo was another of our early company, now also long since departed. For a very few years after my arrival they still hovered about Melbourne, and I recollect gazing in admiration at a cluster of six of them perched upon a large gum-tree near the town, upon the Flemington-road.
As it turned out, Westgarth’s proto-Melbourne – wattle in bloom, kangaroo grass, kookaburras and kingfishers along the river – was set for the drop: a centrepiece of that setting were The Falls, where clear, freshwater cascaded over a rock ledge. They were gone by at least 1858 and across to the west, Batman’s Swamp, with its unparalleled assortment of birds was on its way to becoming a rubbish dump and a home to all manner of noxious industries.
Bird cities: One ecology or two?
As our numbers grew further, habitats were transformed, many eradicated in their entirety leaving only remnants along watercourses.
From the 1970s however, vast numbers of native plants were introduced especially into home gardens inspired in part by Edna Walling, making for food (nectar, grubs, seed and insects) forming a dense understorey of shrubs; in the process serving as nesting sites and shelter for small native birds. For the first time, residents were giving something back and contributing in a meaningful way to biodiversity.
The resulting mosaic of native plants (initially of nonlocal provenance like banksias and grevilleas) along with exotic vegetation created niches for some birds. These were/are mainly the urban adaptors — creatures who have learned to live with us along with invertebrates. Still others are urban avoiders who can’t live with us and suffer when their habitats are overwhelmed with the loss of bushland and farmland due to urban expansion.
Today, both adaptor and avoider populations are in evidence (see map below) and this is necessarily in flux due to seasonality, expansion of settlement and/or loss of vegetation through densification and/or climate change impact.
Bird city can be thought of as an overlay on people city. It’s a go-to for birds (or at least bird watchers) as far as their food and shelter web is concerned, in as much the same way as buildings, roads and transport networks are for us.
Critically, it’s an alternate way of viewing a city like Melbourne for an integrated biodiversity management.
Lower the fences
There are clear opportunities to enlarge local habitat by joining private gardens when rear fencing can be eliminated or made more porous. And wise counsel is at hand through Gardens For Wildlife, a community-based initiative supported by a number of councils. Apart from shrubs and grasses, participants are encouraged to see the value in things like fallen logs and old trees.
It’s what goes on in this space which will burnish rewilding as species seek refuge from desiccation and habitat collapse. And, as the recently concluded national bird count across Australia’s backyards has again underscored, these are the penultimate places for avian and other wildlife and they’re in the private domain, whilst careful attention to parkland and community spaces to create nuclei where small birds and animals can congregate can bolster their efficacy.
In the meantime, trees have become a policy instrument to mitigate heat stress, reduce stormwater run-off whilst adding to (human) amenity. Despite claims that they add to biodiversity – wildlife corridors aside – canopies tend to create spaces for dominant native birds such as the noisy miner and red wattlebird, which, by their behaviour, exclude smaller birds. The evergreen varieties can also limit sunlight reaching understorey plants (and vegetable plots).
But, the real spoiler is catastrophic climate change and there’s been plenty of evidence of that lately. Cities can be vulnerable to fire, especially the so-called leafy suburbs (and those slated for canopy cover) whilst searing winds, rising soil temperatures and declining soil moisture could challenge even the most proficient horticulturists intent on growing their saplings to maturity.
Away from the public policy gaze, further waves of refugees of the non-human variety are coming to town, in search of food, water, shelter and respite from heat and desiccation. Our cities have played host before. The first wave (of adaptors) came with the Millennium Drought, featuring yellow-crested cockatoos, little corellas, crested pigeons and galahs from inland Australia.
City living nowadays often feels like being in a long flight aviary; you could hardly be oblivious to, if not captivated by, the avian sideshow of squawking rainbow lorikeets (voted Australia’s number one bird) even sighted flying down the glass canyons of Melbourne’s Collins Street.
A shared space amid climate turmoil
As Bill McKibben notes, the new nature is constantly destabilising as temperatures climb, so a kind of hyper flexibility is necessary.
The former is reflected in a high degree of fragility and flux across both rural and city environments: new research by Birdlife Australia indicates that something untoward is happening to the quality and productivity of habitats. Put simply, a run of bad seasons can seemingly knock the stuffing out of some regional passerine populations such that they don’t bounce back even when it eventually rains. Without a doubt, the decline of species in the hinterland is complex but identifying and intensively protecting drought refuges could play a key ameliorative role. More research is sure to follow.
Dr Peter Fisher is an Adjunct Professor at the School of Architecture & Built Environment, Deakin University.
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