Environment

TALKING TURKEY

'Superavians' scrape a high life in the suburbs

BRISBANE, Australia — Summer has arrived in the leafy Brisbane suburb of St. Lucia. The only things falling from the trees are exquisitely scented frangipani flowers and the odd possum. Not much to rake up, but somebody next door has been at it half the day by the sound of it.

Scrape, scrape, scrape. Who is this obsessive gardener? It seems rude to peer through the fence, but . . .

He has a bald, boiled-red head and neck, as if he’s been out under the Queensland sun far, far too long. Around his throat hangs a yellow ruff. Apart from that, he’s all in black and using his feet, alternately, to spray leaves and twigs in a 2-meter arc behind him.

No, it’s not the local vicar hunting for his marbles. It’s a turkey.

But it’s not one of your common-or- garden, stuff-it-with-sage-and-onion-type turkeys that’s evaded the festive slaughter. No, this one has nothing to sweat about and no need to be the least bit evasive whatever the season, because this is Alectura lathami, aka the Australian brush turkey — and it is protected by law.

At first glance the brush turkey might not look like much, not compared to the flamboyant birds it shares the suburbs with — kookaburras, pied butcher birds, sulfur-crested cockatoos, and the bright-green-and-red lorikeets streaking between the jacaranda trees pursued by squadrons of crazed “noisy miners.” It stands about normal turkey height and is dusty gray-black all over, apart from the red head and bright-yellow wattle swinging round the neck of the male. Strutting and scampering through gardens and along streets, it certainly resembles some earnest, overworked cleric.

There’s nothing flashy about a brush turkey. But it’s still the most amazing bird in the garden.

The Australian brush turkey is a megapode in the family Megapodiidae. There are 22 species of megapodes scattered across the Australo-Pacific region, with three (the brush turkey, the malleefowl and the orange-footed megapode) native to Australia. The name “megapode,” meaning “big foot,” refers to the long, raking-friendly toes characteristic of the birds in this family.

Sailors’ stories

By bird standards, megapodes do some strange things. When reports of their behavior were taken back to Europe by early travelers, they were for many years dismissed as mere sailors’ stories, logged in the same category as mermaid sightings. There was talk of birds laying their eggs in volcanoes, of chicks hatching underground, and other such nonsense!

Except it was true. One very unbirdlike thing that all species of megapode do is to bury their eggs and allow an external heat source to incubate them. And some megapodes do take advantage of geothermal heat in volcanic soil to do this. And indeed, chicks do hatch underground; they then dig themselves out, and have nothing at all to do with their parents.

In ornithological parlance, megapode chicks are “highly precocial,” which is to say that they are mind-bogglingly talented and well developed when they hatch. Perhaps “superavian” would also be a suitable term, because what these chicks manage to do is surely the equivalent of a human infant lifting a car.

For egg incubation, brush turkeys rely on compost power — which is where all that raking comes in. It is the male’s job to build a mound out of leaves, twigs and soil for females to bury their eggs in.

But don’t imagine a molehill-size, not even the largest one ever heaved up by the heftiest megamole. The average brush turkey mound is 4 meters in diameter and a meter high; it comprises between 2 and 4 tons of material; and it takes up to six weeks to build. Decomposition of vegetable matter warms it from within.

Once a male brush turkey has built his mound, he guards it fiercely and, using his beak as a thermometer, makes sure the core stays at around 34C , sometimes adding material or taking it away to adjust the temperature. (Due to their heat-sensitive beaks, megapodes are also known as “thermometer birds.”)

Meanwhile, females of the species shop around mounds until they find a male they wish to copulate with. (Males man their mounds with this in mind throughout daylight hours, or can be found nearby.) But unlike some species of megapode, the brush turkey is highly promiscuous. No bonding between pairs takes place, and several females may end up laying in the same mound.

The male only allows a female onto his mound for copulation or egg-laying, and on completion of either activity he chases her away. For her flighty part, she has nothing more to do with the eggs, which remain buried at a depth of around half a meter in the center of the mound for about 50 days until they hatch.

Remarkable eggs

Like the birds themselves, though, their eggs are quite remarkable, having unusually thin shells and a very high proportion of yolk compared to the eggs of most other birds. According to Associate Professor Darryl Jones of Brisbane’s Griffith University, an authority on megapodes, a brush turkey’s egg is about 50 percent yolk, compared with around 20 percent for the average chicken’s egg.

Why so much of the yellow stuff?

“The bigger the yolk, the more goodies there are for the chick to develop inside the egg,” Jones explained, adding that the amount of yolk is directly related to the precocity of the chick at hatching. And brush turkey chicks surely need their strength, eyesight and feathers! The seven-week incubation period is long for a bird, but when the chicks eventually kick their way out of their shells (they don’t peck out like normal birds) they are ready for action.

The first Herculean task facing the chick is to dig up through 50 cm of rotting, oxygen-poor compost to reach fresh air. This takes about 40 hours, with most of the distance covered in a frantic burst of digging in the final hour or two.

There is no parental greeting when the chick eventually emerges from the top of the mound, no dust down, no congratulatory worm in the beak or warm regurgitated goo. Not even a gentle prod in the right direction. Nothing.

So, the brush turkey chick is on its own from day one, and, as the professor put it, “has to get stuck in right away!” Getting “stuck in” means foraging for food (grubs and berries), evading predators (cats and foxes), scuttling out of the way of cars — and . . . flying.

“Some people just don’t believe it when you tell them!” Jones said. He was referring to the ability of a brush turkey chick to fly on the very day it emerges from its mound. With no training, no time to build up its strength, and no adult model for inspiration, a newly hatched brush turkey chick can launch itself up into the air, from ground level, to take refuge for the night in the low branches of a tree. That’s what you call precocial!

And that’s about as good as flying gets for a brush turkey. Jones said the furthest he’d seen one fly — “flapping like crazy” — was about 100 meters. Normally they just manage to flutter from branch to branch, up to a maximum roosting height of about 15 meters. But then, looking at a brush turkey, it’s hard not to think it’s high time they had a tail-section redesign. What nature has provided them with resembles the vertical rudder of some long-obsolete airliner.

As for interaction with humans, for thousands of years the high yolk content of megapode eggs made them a valuable source of protein for indigenous peoples. Strict rules on harvesting ensured that supplies were maintained. It helped their survival as well, Jones pointed out, that roast megapode, by most accounts, does not make a particularly appetizing meal.

Hunted as game

In Australia, however, megapodes were virtually wiped out by European settlers who hunted brush turkeys and their cousins as game birds. “They’d eat anything in those days,” Jones said.

By the 1950s, brush turkeys were a rare sight indeed. Since they were designated a protected species in 1974, however, they have proliferated so dramatically in their native territory — down much of Australia’s east coast — that many people now regard them as a pest.

But they’re still a protected pest. You have to be nice to a brush turkey, even if it destroys your garden. Even at Christmas.

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