The march of the brush turkey
This tenacious bird has been defiantly spreading across the east coast to reclaim much of its pre-European range.
AT FIRST I THOUGHT I was seeing things. There had definitely been no over-indulgence the previous evening, but I nevertheless awoke bleary-eyed to the sight of a very large, blackish bird perched awkwardly on the wall of my upper storey balcony. Because I live on Military Road, one of Sydney’s busiest thoroughfares, it seemed a strange place for an Australian brush turkey to roost.
The natural range of the bird – also known as the bush or scrub turkey – stretches along the east coast from far north Queensland to the Illawarra, south of Sydney. It has never been endangered, but after several centuries of habitat loss and predation by cats and foxes, it did become scarce across large areas.
So what was this prehistoric-looking creature doing in the concrete jungle of Neutral Bay, 4km from the city’s CBD, rather than in the deep shadows of the forest? Until the past 20 years or so, turkeys were virtually unknown south of the Hawkesbury River, but, as I soon discovered, they have been on the march in recent decades, determinedly reclaiming their likely historic range. Some Sydneysiders greeted their arrival as a wildlife good-news story, but for others, it meant the outbreak of war in the suburbs.
At Kincumber, on the NSW Central Coast, Sophie Warman and her dog Jasper watch as a brush turkey steals food from the dog’s bowl. Uneaten pet food provides a ready food source for these undiscriminating foragers. (Image: Esther Beaton)
The brush turkey is one of about 22 species of megapode, which means ‘big feet’. These birds don’t sit on their eggs to incubate them, but rather lay them in large mounds of decaying vegetation, relying on the heat generated within. Megapodes are only found in the Indo-Pacific region, with three species in Australia – the malleefowl, orange-footed scrubfowl and the brush turkey. Unique among all birds, megapode parents are the ultimate delinquents, and play absolutely no part in the rearing of their young.
But back to where things begin: the male, with an almost obsessive purposefulness, constructs his mound. These mounds can take on gargantuan proportions as sand, soil, leaf-litter, sticks and twigs are raked into a carefully shaped compost heap with the aid of those big feet. A typical brush turkey mound can measure up to 4m in diameter and stand 1.5m high. Each male will then mate with a number of females, and his mound might eventually contain up to 50 eggs. A female may produce between 20 and 30 eggs in every six-month-long breeding season.
Once the female lays her egg 40–150cm down, however, that’s it – her progeny is entirely on its own, effectively orphaned before its shell has cracked. She plays no part in tending the mound, with the burden of maintenance falling entirely to the male. Climate control is his obsession, and rotting compost his tool in sustaining an even incubation temperature.
To achieve this, he first uses his beak as a probe and inserts it into the mound as far down as the level of the eggs. His palate acts as a thermometer, and, depending on the temperature he senses, he removes or adds leaf-litter as needed.
Similar to the brush turkey, sulphur-crested cockatoos have readily adapted to the suburbs and are often regarded as pests, damaging seedlings and trimming their beaks on garden furniture and cladding. (Image: Esther Beaton)
But exactly why have these tenacious builders and fussy housekeepers successfully reclaimed significant parts of their range in such an altered environment as Sydney? Slow moving and not particularly agile flyers, brush turkeys might easily be caught. They are said to be a good food source, just like their commercially reared namesake, and would certainly have been part of many an Aboriginal meal in pre-European times. Brush turkeys were also on the colonial menu and featured in cookbooks. During the Great Depression in the 1930s they became welcome fare on meagre dinner tables, but legislative protection of fauna and flora after World War II effectively saw hunting cease.
As with so much wildlife, predation of chicks by foxes and cats remains a silent scourge. Sustained fox baiting in recent years has helped, yet, according to Dr Ann Goeth, a Sydney-based wildlife behaviourist, brush turkey expert and educational consultant, the easing of predation is only part of the answer.
A number of changes in the urban environment have helped the turkey resurgence gain momentum, she says, such as the spread of introduced lantana in bush gullies. Newly hatched chicks without any parental protection are vulnerable to predation, so dense thickets provide a perfect haven. This is perhaps a factor in the survival of brush turkeys in my suburb, with a steep, remnant bush gully and patches of lantana several streets away.
“People often feed brush turkeys…directly or unwittingly by leaving their pet’s bowl sitting about outside,” she says. “They are total omnivores and will eat anything.” Uncovered compost heaps are an additional source of profitable pickings, with scraps, and the worms and insect larvae they encourage, eagerly devoured.
A female brush turkey (at rear) defends herself against a male. A male will act aggressively towards a female to ensure she lays her egg quickly, so that his mound becomes vacant again for the next female ready to lay. (Image: Esther Beaton)
On a broader scale, the fashioning of leafy gardens in the more affluent suburbs has unwittingly mimicked the brush turkey’s preferred habitat. As wide lawns have given way to dense plantings and bush gardens, and as garden gurus have exhorted gardeners to mulch well in the crusade to conserve water, the male turkey has decided it is Christmas every day. And this time he is definitely not on the menu.
Loose, moist mulch with which to construct a magnificent edifice is every male’s fantasy. The more plentiful his raw materials, the more palatial his mound, and the more females he is likely to attract. The more females he attracts, the more eggs will be produced. With ample supplies of home-delivered mulch, and an abundance of food and suitable trees and shrubs to roost in safe from predators, brush turkeys moved right into the suburbs and made themselves at home.
Of course, most gardeners do not share a turkey’s view of landscape heaven. Male brush turkeys have been known to demolish a freshly planted and mulched garden in a day, stripping young plants from the ground with seemingly malicious intent. Shocked gardeners, despairing of their ruined investment, have contemplated murder, but instead resort to what they mistakenly consider a more sensitive and less drastic remedy – relocation. “You might as well kill them straight away,” says Ann. Brush turkeys are territorial, and moving them only leads to conflict with other turkeys. Not-so-lucky ones either starve, or end up as road kill.
Whatever the future population dynamics of the species, it seems they are here to stay in urban environments up and down the east coast. Strategies such as using pebbles or gravel as mulch, and protecting young seedlings, might sooth the nerves of anxious gardeners, but I for one can only admire the tenacious bird that came one night to roost on my inner city balcony. A wildlife success story indeed.
This article was originally published in the Jan-Feb 2016 issue of Australian Geographic (AG#130).