Where Song Began
That mob of magpies warbling at your back gate? They’re assassins. The honeyeaters darting from bottlebrush to grevillea? Terrorists. Bellbirds ting-ing high in the misty mountain ash? Bullies. Corellas ranged along a verandah rail? Vandals. And that cassowary by the clothes line could slash you open with a single kick.
Australia’s native birds are the most combative in the world. Noisy, hyper-aggressive, and bigger on average than their northern counterparts, they have evolved in an environment of abundant sunshine, and poor soils have created plants that make more sugar than they can use for growth or seed production. Birds feed on the surplus, in the form of nectar, fruit, manna and lerp. Lerp (the word is Indigenous, from Victoria’s Mallee district) appears as snowy scales on eucalypt leaves and is a delicacy not just to birds but to marsupials and, formerly, humans. Aphid-like insects extrude the starchy, sugary lerp as a shelter in their larval state. Some birds have evolved beaks ideally shaped for prising lerp off leaves, and even feathers patterned with white, lerp-like flecks.
The profuseness of these plant sugars – especially nectar – repays defence of them, making Australian birds gamer than most. The export of eucalypts to the northern hemisphere may even be driving up bird aggression worldwide. In defence of nectar and lerp, local birds in a Los Angeles gum tree will show uncharacteristic fight.
Bird books are plentiful in the shops just now, all of them pitching the case for avian exceptionality. Well, if birds are special, Australia’s birds, according to biologist Tim Low, are most special of all. And sugar-fuelled belligerence is just part of the story.
We’ve all heard how pioneer settlers and explorers would lament Australia’s lack of songbirds. (“What about the magpie?” we always say, betraying our affection for the bird whose call, more than any other, marks the break and close of day – and whose beak, come early spring, might split our scalp.) For centuries, a colonialist mindset dictated that all life forms, humans included, must have originated in Europe. Species and races “discovered” in Africa and the New World were classified as offshoots, by-blows – aberrations, however exotic.
Where Song Began turns that notion on its head, presenting the latest evidence to show that the evolutionary origins of more than half the world’s birds, including all songbirds and parrots, can be traced to Australia.
Biologically speaking, “Australia” includes New Guinea (after all, Bass Strait is wider and deeper than Torres Strait). New Guinea, once also part of the Australian continent, is now a rainforest refuge, a place, says Low, “where old things survive”. Old things such as the gaudy birds of paradise, which originated further south as many as 25 million years ago – before New Guinea’s cordillera landscape had begun to take form.
The lyrebird’s origins lie still earlier, as far back as 45 million years ago. DNA analysis reveals that, together with their near-relatives, scrub-birds, lyrebirds are the sole relic of the world’s first songbirds. They alone retain features of early songbirds, having relatively few vocal muscles and no wishbone. With lyrebirds and scrub-birds forming the lowest branches on the songbirds’ genetic “tree”, and other Australian birds occupying low branches, the unavoidable implication is that all the world’s songbirds have Australian roots. Take that, nightingale.
In fact, as Low (and Shakespeare) points out, the nightingale, by trilling at night, avoids competition with other songsters. A ranking of world birdsong published in 1973 put Australia’s two lyrebirds (superb and Albert’s) in first and second place; the nightingale came 70th.
But songbirds, explains Low, are not simply birds that sing. A suborder of the passerines, or perching birds, they account for a large majority of all living birds. Though some songbird calls are renowned for their melodiousness, many are not: consider the crow. What distinguishes songbirds is that their repertoires, rather than being hardwired, are at least partly acquired in their lifetime. For that incomparable mimic, the lyrebird – whose chicks begin calling while still in the egg – this means that sounds, passed from bird to bird, outlive individuals. Low tells of lyrebirds introduced to Tasmania in the 1930s; three decades later their descendants still made the cry of the whipbird, a species confined to the mainland.
Parrots, too, had their origins in Australia, where they still keep their firmest claw-hold. Among parrots, and Australian bird species generally, co-operative breeding is the norm. In the safety of a mob or flock, group breeders can afford to be more raucous and aggressive than the paired breeders that predominate in the northern hemisphere. They also have less use for the courtship niceties of melodic song.
Low points to some of Australia’s remarkable birds – the cassowary, largest and most fearsome rainforest inhabitant; parrots that do “everything” (drink nectar, crack nuts, dig roots); and flightless rails – as evidence of mammals, particularly predators, that were “missing” from our continent’s evolutionary rollcall. And, intentionally or not, he invites a comparison between Australia’s bickering birdlife and the territorial disputes inherent in his own field of biogeography: northern orthodoxersv Gondwanan upstarts, genetics v fossils.
Any book of this sort, stuffed with the fruits of long experience, wide travels (is there anywhere Tim Low hasn’t been?) and deep research, is bound to send the reader reeling from its pages chirruping the hardwired call of the Lesser Party Bore (Did you know…? Would you believe…?). The learned portion of Party Bore’s call varies a good deal. Did you know the glossy black cockatoo of Kangaroo Island is left-footed? Would you believe that parrots and falcons both smell “slightly nutty”? Oh, and 97 per cent of bird species lack a penis, instead performing the “cloacal kiss”. Try warbling that, next time you find yourself sipping on nectar. FL
Viking, 416pp, $32.99
This article was first published in the print edition of The Saturday Paper on Jun 28, 2014 as "Tim Low, Where Song Began".
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