Earth was a drastically changed place following the Cretaceous–Paleogene (K-Pg) event 66 million years ago; the fifth mass extinction that wiped out terrestrial dinosaurs and 76% of species worldwide. Ecology followed suit, and given the abundance of vacant niches and the lack of competition, a period of rapid evolution transpired. The most significant of these evolutionary events, in the context of palaeontology, was the domination of land by mammalian life. A strange twist in the tale of evolution can be traced through the evolutionary development of cursoriality — the biophysical ability to run — in some birds, which materialised in changes to their muscular and skeletal architecture. Selective pressures allowed the evolutionary flourishing of cursorial birds, particularly in small island archipelagos where terrestrial competition was less polemic. New Zealand, a biogeography devoid of large predators, where the first Māori settlers arrived as late as 1300, is home to more species of cursorial birds than anywhere else in the world. From our human perspective, it seems cruel for evolution to favour the development of flightlessness - for we have always dreamed of flying.
New Zealand’s order of moas — nine now-extinct flightless birds endemic to New Zealand — were the only birds to completely lose their wings. Their extinction is thought to have taken less than a century, concurrent with the arrival of the Māori, who hunted moa for sustenance. All other flightless birds retain the physical apparatus for flying (wings) in theory, or at least some remnant of it. These vestigial remnants are often thought of as akin to the human appendix: an anatomical feature or behavioural trait that no longer seems to serve a purpose in existing organisms, but is retained in a species across generations through reproduction. However, ethno-ethological accounts exploring the societal function of wings in flightless birds have shed light on their use in courtship practices. For example, wings are used by flightless male ostriches to demonstrate their body size in relation to sexual competitors within their species. The societal structures of flightless birds often favour greater body mass in males due to their incubatory role; for instance, male penguins famously protect their eggs for up to three months prior to birth, a behavioural trait shared amongst emus, ostriches, and cassowaries. Gradually, these birds evolved and increased in gigantism, but this didn’t result in their wings becoming useless; rather, their wings adapted to a role dictated by their cultural coding. The wings of these birds are reminders of an avian past.
Primates that took to the skies
The fastest way to get from point A to point B? ‘As the crow flies’, the saying goes. Flight, or flying, is the fastest way for someone or something to move between two places in a straight line. To fly is to avoid obstacles, to avoid the friction of distance experienced by terrestrial animals, or land-dwelling organisms. Flying, therefore, has been an aspiration of humans for millennia. From shamanic flight journeys to the earliest attempts at mechanical flying, our knowledge of aerial transport came from the natural world; from the nonhuman animals we share the ‘Eairth’ with, as cultural ecologist David Abrams would say. ‘Eairth’, he contends, presents our existence in and of the air, a consideration of Earth’s being beyond its lithosphere. Determining the first human attempt at flying, however, is not an easy task - perhaps an impossible one. Children flapping their arms in an attempt to take off with the pigeons is perhaps an ancient activity; the earliest attempt at biomimicry in the form of winged human-like figures and scenes can be found in cave paintings from prehistoric times dating back 4,300 years.
Naturally, some form of human flight also occurs in most religions and myths.The story of Icarus is one of the oldest and best-known examples of human flight, a story dating back to around 1400 B.C. Daedalus and Icarus, father and son, build wings from wood, wax, twine and bird feathers. Whilst Daedalus survives his flight attempt, Icarus dares to go too close to the sun, which melts the wax that meld his wings together, and he falls to death. Whilst there is of course no way of proving the historical basis for Icarus’ death, we can be sure that other humans throughout history have risked their lives by trying to build artificial wings According to historians, the legend of King Bladud may, for example, be one of the earliest tales to have some truth to it. King Bladud, King of the Britons and father of King Lear, is said to have attempted to fly using manufactured wings in around 850 B.C. The story goes that the quasi-legendary monarch climbed the temple of Apollo - in what is now modern-day London - donned his wings, and unsurprisingly, fell to his death. From Roman Emperor Nero’s parties, to Chinese sailors taking to the air via purpose built kites, humans have died in their attempts to occupy the skies. Human remains can be found splattered throughout history over the course of the last 2,000 years. In The Prehistory of Flight by Clive Hart, only around a dozen of the fifty or so attempted flyers he documents managed to remain in the air, gliding for only a few fleeting seconds before grounding.
The National Air and Space Museum, a Smithsonian Institution in Washington D.C., and the Fédération Aéronautique Internationale (FAI), however, name the Wright brothers as the first people to successfully fly. According to their definition, the Wrights were the first to make a sustained, controlled, powered, heavier-than-air manned flight at Kill Devil Hills in North Carolina, USA on December 17th, 1903. Significantly, the two brothers were no different from their predecessors in the history of attempted flight, in that they looked to the biological world for inspiration. Often cycling out in the Pinnacles, a picnic area south of Dayton, Ohio, the brothers would sit and observe the flights of birds, seeking inspiration for their inventions. However, they were among the first to focus on soaring birds as models for flight, rather than the flapping wings that Icarus and King Bladud had opted for. From these observations they developed their wing warping theory in the summer of 1899, after watching buzzards twisting the tips of their wings to surf the waves of the wind. The choice of buzzards proved crucial in the development of human aviation. The wing tip twisting they observed does not occur in smaller birds, who change the speed of their flapping wings in order to turn rather than changing the shape of their wings. This knowledge was formalised over a century later through the analysis of high-speed videos of birds flying by researchers at the Universities of Delaware and North Carolina. The development of drones at the University of Oxford among other places also relies on bird observations in order to perfect steady flight. The history of evolution has granted engineers and inventors countless moments of inspiration. The natural selection of certain traits for flying emerged via the natural world’s very own trial-and-error experimentation, operating on geological timescales often too broad to imagine. When we experiment, we play with the possibility of another reality. Biomimicry can be thought of as a means of exploring the trails-and-errors of nonhuman life throughout evolution.
If we look to history, many early flight pioneers were concerned with making model birds. Archytas of Tarentum, for example, created a model bird that could glide through the air in the 4th Century B.C. More famously, Leonardo da Vinci produced designs for an ornithopter - essentially a plane with flapping wings - in the 16th Century, although it is unclear whether it was ever manufactured or tested. In the tale of Icarus, bird feathers were used directly as a material, the bodies of birds being crucial in the duo’s attempt to take flight. More harrowingly, and more recently, these body-borrowings have extended to the commercial airline industry which in itself has also had a different relationship with birds since its beginning.
Collisions with flocks of birds can be extremely dangerous for aeroplanes. Canada Geese were the cause of narrowly-avoided catastrophe nicknamed ‘the miracle on the Hudson’ on January 15th 2009. US Airways Flight 1549 was brought down by a flock of Canadian Geese who were caught in the engine of the Airbus A320 that was flying from New York to Seattle. Luckily, Captain Sully managed to land the plane on the Hudson river with all 155 people on board surviving, with only a few serious injuries among the passengers. In the US alone, the Federal Aviation Authority reported 11,315 bird strikes in 2013 up from 1,851 in 1990. Actual bird bodies have been used to test how the engines of aeroplanes cope with collisions before, and increasingly since that near-fatal accident over the Hudson. From the culling of birds in response to the crash - almost 70,000 birds were culled in the aftermath - to the use of chicken cannons to test whether engines can cope with bird strikes, the lives of those who inspired humans to take flight are cut short in the pursuit of human aviation.
The Extinction of Flight
Rails, or Rallidae, are a large family of small to medium sized birds that dwell on the ground, including coots, crakes, and gallinules. They inhabit every continent except Antarctica and are often found on islands. Between 136,000 and 240,000 years ago, a group of white-throated rails left the island of Madagascar off the East coast of Africa and departed for an island in the Aldabra atoll, the world’s second largest coral atoll situated in the Indian Ocean, which is part of the Outer Islands of the Seychelles. When they arrived, they were greeted by an abundance of accessible food and a comforting lack of predators. As they gorged on the food and lazed around stress-free, the Rails eventually evolved to lose their ability to fly, which was simply no longer required for survival. Flight itself, as a property of the animal, became extinct, the same way it did in ostriches and dodos amongst other flightless birds. The ancient Rails of the Aldabra atoll, however, succumbed to a catastrophic flood when rising sea levels wiped out birds that were unable to make an escape. The Rails became extinct, much like their ability to fly did when they originally settled on the island.
Recent archaeological digs on the island have revealed fossils that tell another story of flight and extinction. Before and after the devastating flood that wiped out the Rails, it appears that another group of white-throated Rails preceded and followed their ancestors in making the same journey to the Aldabra atoll. Amazingly, the new arrivals also went on to become flightless, demonstrating the deep ties between flight and landscape. This is an example of the rare phenomenon of iterative evolution, which occurs when extremely similar species evolve from the same ancestor at different times. The rarity of cases of iterative evolution demonstrates how the relationship between flight and landscape is not deterministic, but rather deeply connected and contingent on a number of environmental factors; factors upon which, today, humans are having an increasing impact. As the case of Aldabra Rails shows, flightless birds are at an elevated risk of extinction due to certain (relatively rapid) landscape and ecological shifts. Moreover, in the Anthropocene – an era of accelerating environmental change – flightless birds are some of the most at-risk animals on the planet; invasive species, hunting, and industrial agricultural practices all have serious consequences for these animals.
An Ironic Fate
Rails can still be found on the Aldabra Atoll today. As flightless birds, they belong to a category of wildlife with an increased rate of extinction in the Anthropocene. As their ability to fly became extinct through the process of evolution (multiple times in the case of the Aldabra Atoll), they now face the same fate as their capacity for flight in many places around the world. Rapid global decline in bird numbers accompanied by the threat of extinction to flightless birds is occurring at the same time as humans become ever more active in the skies. This tragic irony is not lost here, as the animals that inspired us to take to the skies in the first place suffer the consequences of anthropogenic activity, sometimes as a direct result of human aviation. Around 30% of our greenhouse gas emissions are released from the transport sector,and the aviation industry is one of the fastest-growing polluters in the world. A long-haul flight can produce more greenhouse gases than many people from certain countries do in a year. Reducing the friction of distance has become more than an experimental pursuit, but is now tied inextricably to capital. Flight allows the capitalist to be mobile but also to produce profit from flying - the aerospace industry is worth around $800 billion. This profit is inherently connected to the death of birds; the pioneers of flight are being rapidly replaced by their techno-flying relatives. The majority of flights, moreover, are taken by a small minority of relatively wealthy Westerners, those wealthy enough to profit at the planet’s expense.
As we take to the skies in aluminium tubes, modelled on the chassis of birds provided to us by evolution, we emit large quantities of greenhouse gases into the atmosphere at an unprecedented and unsustainable rate. The flightless birds that took to the land and evolved the biophysical infrastructure to accommodate cursoriality have been left vulnerable by evolution: exposed to the anthropogenic mass extinction largely caused by capitalism’s disregard for ecology. The global ecological crisis is at a tipping point. As a select and privileged number of human beings justify their disregard for environmental consequences under the banner of progress, we too are flying close to the sun, the wax within our interwoven feathers uneasily and anxiously expressing its intention to melt. Flightlessness is at the interface of extinction and evolution, entrenched within deep geological and evolutionary timescales. It is a useful lens with which to inspect our place in the contemporary world. Evolution and extinction are in balance with one another, expressing the sensitivity of biodiversity to rapid environmental and ecological change, ironically exacerbated through biomimicry. Perhaps it is time we find joy in our own flightlessness, and learn to dwell alongside the Rails.
This essay was originally printed in FLIGHTS 2020.
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4. Ibid., according to Fabyan’s “The Chronicles” dated A.D. 1596.
5. Hart, C. 1985. The Prehistory of Flight. Berkeley, CA: University of California Press,
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11. Geographer Charlotte Wrigley, notes how the Canada Geese that disrupted US Airways Flight 1549 were not even local birds, making the culling of birds in the local area a useless activity in preventing further bird strikes.
12. Hume, J. and Martill, D. 2019. ‘Repeated evolution of flightlessness in Dryolimnas rails (Aves: Rallidae) after extinction and recolonization on Aldabra’. Zoological Journal of the Linnean Society, 186(3): 666-672.
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17. It is important to note that this ‘we’ refers to the relatively wealthy Westerners who take the vast majority of flights globally. Whilst air travel expands in the global south, flying remains a privileged activity largely and relatively cheaply available to those in the global north.