The Australian brush-turkey

The brush-turkey (Alectura lathami) belongs to the megapodes, the "mound-builders," an ancient lineage that abandoned the warm parental body most birds incubate with and handed the job to decay. Instead of sitting on a clutch, the male rakes together a huge mound of leaf litter and soil — commonly a metre or so high and several across, the patient labour of weeks — and the eggs are laid deep inside it, incubated by the heat of the rotting vegetation. The real marvel is the management. The male keeps the mound near the mid-thirties Celsius the eggs need, testing it with his bill and adding or scraping away litter to hold the temperature — a living thermostat in feathers. The chicks hatch far down in the mound and must dig their own way up through it, a slog of many hours; they surface already independent, having never met a parent, and can flutter up into a tree within hours of reaching the light.

Set that against the coast's specialists and the brush-turkey is the instructive counter-case. Where the koala is staked on particular feed trees and the acid frog on a particular chemistry, the brush-turkey depends on remarkably little in particular: a supply of leaf litter to build and heat the mound, enough moisture to keep the compost working, shaded ground to rake, and a broad, opportunistic diet of fallen fruit, seeds and invertebrates it turns up as it scratches. It is at home in the closed subtropical rainforest — where the deep, damp litter is richest — but by no means confined to it, spilling out through the wetter eucalypt forest, the scrubby edges, and, increasingly, the mulched gardens of the suburbs. Read against what it needs, the picture is the mirror image of the specialist's bargain: its requirements are cheap and near-ubiquitous, so the broken, edge-riddled landscape that starves a specialist is, to a brush-turkey, simply more habitat.

It was not always thriving. Hunted hard in earlier generations and pushed back from the settled districts, the brush-turkey has returned in force and spread back into the suburbs it had been driven from, to the mixed feelings of gardeners whose flowerbeds it redistributes. It is a genuinely cheering note in a fauna full of decline — proof that an odd, robust, all-purpose way of life can not only survive the human landscape but settle happily into it, and a reminder that "why is it here?" is answered the same way for winners and losers alike: read what the animal needs against what the place supplies. For the specialists that reading spells trouble. For the brush-turkey, raking up the mulch by the barbecue, it spells opportunity.