It feels like a miracle that the Andean condor (Vultur gryphus), the world’s largest flying bird, with a wingspan of up to 3 metres (10.5 feet) and weighing up to 15 kg (33lbs), can fly at all. Yet these elegant creatures actually spend most of their lives in the air, as on the ground they are vulnerable to predators, and they need an exorbitant amount of energy to lift off.
So how does the condor, ungainly on land, coast through the skies so effortlessly as to earn their revered status in South American mythology and culture? Professor Emily Shepard of Swansea University (UK) and an international team of scientists have just completed a study addressing that very question.
The study was not a brief one and the team had to experiment in different locations as condors would refuse to land in certain areas even with a waiting carcass below. As the researchers later discovered, since takeoff consumes 75% of the bird’s usual flapping, the associated flight cost of landing leads the Andean condor to be specific in its foraging patterns.
Drinking the local “mate” brew in the rolling hills of the Patagonian steppe, the team waited for “nature’s undertakers” circling overhead to descend on strategically placed carcasses, then tagged the birds with a tracker to record each wingbeat and emit a GPS location to which the team could follow until the tracker self-released when the condor came to roost. If luring the condors was challenging, finally retrieving the flight recorders added a whole new level of treachery and patience. “The team had to walk tens of kilometres, travel on horseback, use crampons, and cross rivers while tied together with ropes, in order to access the condor nests,” recalls Shepard.
The results they found, however, were staggering enough to justify the weeks of perilous excursion. Not only is the condor our largest flying bird, but they discovered that it stays aloft without almost any flapping of its wings.
As condors glide through the skies of South America, they expertly move between air currents and rising thermal bubbles, allowing them to spend 99% of their flight without flapping at all, with one particular condor traveling over 5 hours and ~172 km (100+ miles) on a single glide.
Their honed skill is imperative, as an unintended landing for a condor could mark the difference between death and survival. However, despite their innate skill for navigating our troposphere, the invisible “airscape” can play tricks on them, as the rising of warm air bubbles may be inconsistent due to weather or seasonal variation.
The condor is an expert of the sky, and reveals clues to a hidden map of our air currents today. It also provides a clue into history, where long-extinct bird species that far surpassed the size and weight of the condor were somehow able to lift off the ground. As condors circle overhead, their wings outstretched and still, one can imagine how the Argentavis magnificens, a bird with a wingspan more than twice that of the condor, was once able to soar in the prehistoric skies, and once again reveals to us how everything there is on earth is the birth-child of what was once here before.
For The Yucatan Times Wildlife
Raquel Anais
—
Raquel Anais is a freelance writer specializing in environmental features, published across a variety of international online and print media.
