Toward the end of his highly enjoyable book Where Song Began, Tim Low informs us that “it might be said that the world has one hemisphere weighted towards mammals and one towards birds.” The hemisphere weighted toward mammals is the northern one. And Low makes a convincing case that, in the south, birds of a most extravagant type occur. But is the southern hemisphere truly weighted toward birds? One window into the question is through bird–human interactions. We humans are used to getting our way with nature, but in the Antipodes birds occasionally gain the upper hand.
Such was the case when, in 1932, Australia decided to declare war on the emu, an enormous flightless bird whose image is emblazoned on the country’s coat of arms. Sir George Pierce, Australia’s defense minister, was beseeched by farmers from Australia’s southwest for deliverance from the ravening creatures, which were swarming out of the desert in countless thousands, driven south by drought. Sir George agreed to help, and so was sparked what would become known as the Great Emu War.
Major C.P.W. Meredith of the Seventh Heavy Battery of the Royal Australian Artillery was ordered to proceed with armed troops to the environs of Campion, a small town located near the emu “front line.” There, the army was to use Lewis guns (machine guns) to disperse the invaders. Hostilities commenced on November 1, but the birds were at such a distance that gunfire was largely ineffective. The next day, a thousand emus were seen advancing on a dam. Meredith and his troops were in a splendid position to inflict maximum casualties, but after only fewer than twelve birds were killed the Lewis guns jammed. Frustrated by the fleetness of the birds, Meredith had the machine guns mounted on trucks, but the emus easily outran the vehicles.
A month later, a crestfallen Meredith was forced to explain to the Australian Parliament that the war had been lost. He said of his foe:
If we had a military division with the bullet-carrying capacity of these birds it would face any army in the world. They can face machine guns with the invulnerability of tanks. They are like the Zulus whom even dum-dum bullets could not stop.
The war was not over, however. Irregular troops in the form of bounty hunters were enlisted, but even they could not subdue the foe, and the conflict continued for decades.
Being defeated in war by one’s avifauna is ignominious. But Australians are inured to being stung, bitten, envenomated, or outright eaten alive by a hostile fauna. Incredibly, Low claims that even Australian songbirds are dangerous. The Australian magpie looks like a very large jay, and when it breeds in the spring, it turns the country into a battleground. Magpies defend their territory by “dive-bombing” “invaders” from the rear, which is why you may see Australian pedestrians waving umbrellas into a clear sky, or bicyclists with rearward-looking faces painted on their helmets.
Magpies, according to Low, “can distinguish kindly adults from scheming boys.” Postmen are particularly detested: Australia is perhaps the only country on earth where they fear songbirds as much as dogs. And those whom magpies particularly loathe will be identified and targeted, even if they haven’t been seen for years. Low tells of a “terrorized school in Brisbane” where “throngs of screaming parents at the gates were trying to get their terrified children to run quickly across the open area to the main building where the school medical officer was waiting with the first aid kit.” Over two weeks, more than a hundred children had their faces cut by magpies. But the damage can be much worse. Magpies will sometimes land in front of a person they despise, and then leap at their face. Each year, one or two people are stabbed in the eyes.
Surveys indicate that 85 percent of Australians have been harassed by magpies, so it seems remarkable that a magpie that blinded a boy in the Queensland town of Toowoomba was relocated rather than killed. In 1856, the naturalist George Bennett said of these remarkable creatures, “It is a bird of much importance in its own estimation, struts about quite fearless of danger, and evinces, on many occasions, great bravery.” It says something of the national character of Australians that they can forgive such a creature almost anything.
Australia and New Guinea are joined at times of low sea level and share many species in common. Consequently, Low uses “Australia” as shorthand for Australia–New Guinea throughout his book. The flightless cassowary inhabits the rainforests of New Guinea and north Queensland. The size of a man, its gaudy purple, yellow, and red head bears a high crest and a frighteningly malicious eye. On its foot is a four-inch-long dagger-like claw, which Low suspects is used to “kill many more people in New Guinea than tigers do in most countries in Asia.”
I worked for twenty years in New Guinea, and am certain that Low is correct. It’s the male cassowaries that incubate the eggs and care for the chicks, and they will attack out of the blue if you go anywhere near their young. There being so very few accounts of a cassowary attack (because most happen among remote tribes living in dense jungle), it is worthwhile recounting one instance here. Professor Joe Mangi is a friend and archaeologist who told me of an attack that occurred in the 1980s in Papua New Guinea’s Southern Highlands. The victim had found a cassowary nest and was taking the eggs (which are bright green and up to five and a half inches long) when he heard a booming noise. He barely had time to grab his machete and leap to meet the attacking bird. They met mid-air, the man severing the cassowary’s leg, the bird disemboweling the man with its claw.
Joe dispatched the wounded cassowary and gathered the man’s intestines, which were stretched over yards of forest floor. Uncertain about medical treatment, he emptied the entire contents of his medical kit onto the guts before gathering them up and stuffing them back into the abdominal cavity. When the villagers arrived they daubed their faces with white clay and began mourning: they considered the victim a dead man. With the nearest airstrip a full day’s walk away, Joe urged that a stretcher be made. But the victim sat up and said, “You take my first wife. You the second. And you get the pigs.” Joe’s reassurances that the man would survive if he could be got to a hospital were as cries in the wilderness.
Carrying the stretcher over the broken limestone country was hard going, so Joe sent two boys ahead to request fresh carriers. They never arrived, and when Joe got to the village he found it in mourning for the victim. The village chief was so enraged at the youths, who had told him that the victim had died, that he struck them on the head with a piece of timber. Now the cassowary had claimed three victims.
When the stretcher carrying the first victim approached the airstrip an aircraft was heard, but Joe’s feet were so torn that he was crippled, so he sent a muscular villager ahead to ask the pilot to wait for the casualties. The young Australian pilot was naturally alarmed at the sight of a Papuan charging toward his plane, his grass pubic covering waving wildly in the breeze. He leaped into the cockpit and began preparations for takeoff when he noticed that the Papuan, who spoke no English, had grasped the propeller. Joe arrived in time to explain things, and the victim made a full recovery.
Low offers a curious aside about emus and cassowaries. They are some of the few birds that possess penises. Only 3 percent of all bird species are so endowed, the other 97 percent getting by with a “cloacal kiss” to transfer sperm. Possession of a penis is an ancestral condition inherited from the dinosaurs, and just why most birds have lost their penis is a curious question. Low puts it down to hygiene, saying that “birds face more disease risks than mammals since they use the same opening for defecation and sex.” But what to make of the Argentine lake duck, whose sixteen-inch phallus is longer than its body? Low offers the rather feeble observation that ducks are cleaner than most birds because their bottoms are immersed in water. But if there is no disease risk, then why do some female ducks possess multiple false vaginas?
Another curious question concerns why Australia’s birds are so aggressive, and often so large. The continent’s mammals are mostly marsupials, and Low claims that they are rather poor competitors for the birds, so birds have come to dominate some ecological niches, including fruit-eating in tropical forests—a niche exploited by cassowaries. But there is more to the story than that. Strange as it may seem, neither the cassowary nor the magpie can claim to be Australia’s most aggressive bird. That title must go to a rather drab gray member of the honeyeater family known as the noisy miner.
Accused in a scientific paper of “despotic aggressiveness,” the species has been recorded driving off fifty-seven rival types of bird. Indeed the noisy miner’s aggression has led to it becoming “one of the most important mechanisms through which habitat fragmentation and degradation threaten populations of eastern Australian woodland birds.” “They will turn on almost anything,” Low says: “koalas, cows, bats, pigs, snakes, lizards, people,” as well as other birds. And worse, they recruit allies in their bullying, including the aptly named butcher bird—a sharp-beaked, shrike-like predator that the noisy miners leave alone—provided they refrain from taking their eggs and young.
Noisy miners will even recruit humans as allies. Some years ago, a great fracas emanating from a mob of noisy miners outside my house in Sydney induced me to leave my work and investigate. As I stepped outside, the birds fell into silent expectation. Looking down, I saw a python. I got the distinct feeling that the noisy miners expected me to deal with it. But I like pythons, so I left it and returned inside. The howl of disappointed rage emerging simultaneously from dozens of beaks had to be heard to be believed. To get any peace, I was forced to move the snake.
Many Australian birds are highly intelligent, a factor that contributes in no small measure to their success. Parrots and songbirds—groups that thrive in Australia—have large brains relative to their body size. According to research, they can outdo apes in some tasks, exhibiting “cultural transmission of tool design, theory of mind, and Piagetian object permanence to a high level.” Like many humans, they are also playful. The apogee of avian intelligence arguably occurs on New Caledonia—an island adjacent to Australia—where a native crow (a songbird) makes a variety of tools, including hooks.
Low notes that “complicated calls and intelligence seem to go together.” There may be a link here with our own species. Charles Darwin wrote that birds
have nearly the same taste for the beautiful as we have. This is shewn by our enjoyment of the singing of birds, and by our women, both civilized and savage, decking their heads with borrowed plumes….
Indeed it may be that songbirds taught us humans how to sing by “influencing the evolution of human acoustic perception.”
The highly social nature of many Australian birds is also notable. In some species it’s not only the parents who feed the chicks, but distantly related or even unrelated birds. According to Low, white-winged choughs—a large black bird with a sinister-looking red eye—even practice a form of slavery. They abduct fledglings from the nests of other choughs and induce them to feed their own chicks. But in this “dishonest society” the abductees sometimes only fake helping.
For those feeling safe from large, intelligent, and aggressive birds in their mammal-dominated northern hemisphere homes, Low has some alarming news. Australian birds have taken over the world. The remarkable fact has been revealed through genetic studies, and when first announced it was flatly disbelieved, for it flew in the face of all that we thought we knew about the way evolution works. Prior to the discovery, it was thought that species from the larger, northern continents were competitively superior, which means that faunal exchange should be one way—from north to south. Darwin put the idea as succinctly as anyone:
I suspect that this preponderant migration from the north to the south is due to the greater extent of land in the north, and to the northern forms having existed in their homes in greater numbers, and having consequently been advanced through natural selection and competition to a higher stage of perfection, or domineering power, than the southern forms.
The first significant questioning of the idea came from Charles Sibley, an ornithologist working at Yale in the early 1970s, who discovered that if he boiled double-stranded bird DNA, when the mixture cooled the strands would recombine. He found that if he mixed the DNA of two species, the strength of the rebonding was an index of evolutionary relatedness. His work revealed that “Australia’s robins, flycatchers, warblers and babblers were not what their names suggested.” Instead they were part of an ancient Australian group that over time had come to resemble birds from elsewhere. They were, Sibley concluded, part of an ancient songbird radiation as diverse and unique as Australia’s marsupials.
Since Sibley’s day, genetic studies have become immensely more sophisticated, and some have revealed entirely unexpected relationships. Several detailed genetic studies, including a comprehensive mapping of retroposons (repetitive DNA fragments that insert randomly into the genome), for example, agree that songbirds, parrots, and falcons are one another’s closest relatives, and that this group probably originated close to the time of the dinosaur extinction in what was then the Australian section of the supercontinent Gondwana. It seems astonishing that falcons and robins could be more closely related to each other than are falcons and hawks. But the avian body plan is highly restricted by the requirements of flight, and because there are so few options for becoming a flying predator, convergent evolution is widespread among birds.
Occasionally, anatomists and behaviorists discover clues to relationships by reexamining the earliest members of a bird family tree in light of genetic studies. New Zealand’s kea, for example, is a member of the most basal branch of the parrot family tree. It is a predator with a vicious beak, and can kill and eat sheep, making a relationship between parrots and falcons seem a little less improbable.
Songbirds are by far the largest and most successful group of birds in the world. Their five thousand species, divided between forty orders, make up 47 percent of all bird species. Eighteen of Britain’s twenty most abundant species are songbirds, as is the most abundant wild bird on earth, Africa’s red-billed quelea, of which 1.5 billion are thought to exist. The great majority of songbirds fall into just one order, the perching birds or Passeriformes, which take their name from the Latin term for the sparrow. All of the little birds that forage among leaves are perching birds, as are crows and magpies, and one thing that sets them apart from all other birds is the possession of a hind toe operated by an independent set of tendons.
In 2002 a genetic study revealed that New Zealand’s wrens sit at the base of the songbird family tree. They are mostly extinct, and the survivors don’t sing at all, instead vocalizing with high, thin squeaks. Other studies show that the second branch off the songbird family tree includes Australia’s lyrebirds and scrub birds, while the third includes Australia’s tree-creepers and bowerbirds. None of these branches has many species, and all are exclusively Australasian. This abundance of early types, along with the discovery in Australia of the oldest songbird fossils in the world, provides convincing evidence that Darwin’s dictum, at least when it comes to the songbirds, is wrong. One of the most successful groups of vertebrates ever to have evolved—the songbirds—originated in Australia and has since spread around the globe.
Low has some fascinating ideas about why and how the songbirds evolved. The group that first spread successfully outside Australia seems to have discovered a new ecological niche that developed, paradoxically, courtesy of Australia’s infertile soils. Australia is low, flat, and geologically comatose, so its soils have not been rejuvenated by volcanoes, the uplift and erosion of mountains, or glaciers for tens of millions of years. As a result, its ancient soils are largely leached of nutrients, so plants growing in them tend to hoard what nutrients they can get. Nectar, being sugary, requires minimal nutrients in order to be produced, and Australia’s eucalypts and their relatives are some of the greatest nectar producers on earth. Moreover, their flowers are simple in structure and animals require no special adaptations to harvest the rich liquid, making it attractive to a wide range of species. Visitors to Australia will easily see the consequences: flowering gum trees pulsate with the screams of lorikeets and the raucous cries of half a dozen species of honeyeaters. Relatively small species like noisy miners have triumphed in this melee only by becoming highly social, aggressive, and intelligent.
Beginning around 30 million years ago, Australia’s aggressive, social songbirds found their way across the stepping-stone island arc lying to Australia’s north. When they reached mainland Asia, an entire new world opened to them. The fossil record of Europe, which is particularly complete, tells the story of what happened next. Prior to the arrival of songbirds Europe was host to myriad primitive birds such as mousebirds (a few of which survive today in Africa). As soon as the songbirds arrived, they vanished permanently. The initial songbird invasion was no one-off event. Just as Africa has been the point of origin of one hominid type after another—from Homo erectus to modern humans—so Australia has acted as a fountainhead for songbird lineages that have gone on to spread around the globe. One example of a more recent invasion concerns the orioles, a group of songbirds that, until a few million years ago, were most probably restricted to New Guinea.
The oriole family is a small element in New Guinea’s avifauna. But it does include the world’s only poisonous bird, the hooded pitohui. So toxic are its feathers and skin that merely handling a stuffed museum specimen that is decades old can induce nausea. It was only after one branch of this family reached foreign shores and gave rise to all the Old World orioles that orioles became an avian success. Fans of the Baltimore Orioles should know, incidentally, that the bird is a member of an entirely different family, the Icteriidae, which is restricted to the New World.
Where Song Began provides a novel interpretation of Australia’s avifauna that will enrich the understanding of anyone interested in birds. As a professional biologist familiar with much of its matter I found myself again and again astonished. Indeed, it seems to prove that what Mark Twain said of Australia’s history—that “it does not read like history, but like the most beautiful lies”—applies equally well to Australian nature.