(MENAFN – The Conversation) Andean condors, at 10kg or more, are among the world’s heaviest flying birds. Once birds get this big, the energetic costs of flapping are so high they instead rely on currents of rising air to travel long distances.
My colleagues and I are experts in bird flight and we asked just how little flapping these condors and other soaring birds can get away with, and if there are particular environments or weather conditions that are more costly to fly in. Very little is known about what actually makes these birds work, and only recently have we been able to use tagging technology to spy on them in the sky.
A talented colleague of mine at the University of Swansea developed high-tech ‘flight recorders’ for our team to attach to condors and record each and every wingbeat as they searched for food. The results of our five-year project in Argentina are now published in the journal PNAS .
How do you catch a condor? It takes time. A lot of time. As a field team we spent days sitting in the Patagonian steppe, drinking maté and waiting for the condors to land at sheep carcasses or bones left over from the slaughterhouse that had been specially placed to try and tempt them down.
This was the easy part. Ugo Mellone, Author provided It turns out putting the tags on is much easier than getting tags back. Our tags record 320 different data-points per second, so much information that it is not possible to send the data back via the phone or satellite network. Instead, we designed a system so that the tags would fall off the birds when they were roosting on their cliffs at night. Using a GPS location, we found out where they spent the night and used a VHF signal to recover the tag from the bottom of the cliff.
It sounds simple. But there are very few roads in Patagonia, and in order to access the condor roosts the team had to walk tens of kilometres, travel on horseback, use crampons and cross rivers while tied together with ropes. For every tag that we found, we lost at least seven. A key breakthrough came when we started tagging immature birds, as they spend their time at communal roosts, which tend to be more in the gently rolling hills of the steppe, rather than in the high and inaccessible Andes where the adults often nest.
The vast dry steppe of Patagonia with the Andes mountains in the distance. Alexandr Vorobev / shutterstock Our results showed that on average, condors fly for three hours a day, but they flap for less than two minutes of this just 1% of their flight time. One bird even flew for more than five hours without a single flap, covering 172km. Surprisingly, the amount they flapped hardly changed whether they were in the Andes or the steppe, or whether it was windy or not.
Moving between weak thermals of air seemed more challenging as birds flapped towards the end of the glides, when they were likely to be close to the ground. This is a critical time as birds need to find rising air to avoid an unplanned landing.
Thermals can behave like lava lamps, with bubbles of air rising intermittently from the ground when the air is warm enough. Birds may therefore arrive in the right place for a thermal, but at the wrong time. And the lengths of time when the bubbles are not rising sufficiently rapidly to be useful to a condor will be longer when thermals are weaker.
Bird researcher Orlando Mastrantuoni recovers a condor tag in the Andes mountains. Orlando Mastrantuoni, Author provided Nonetheless, even in weak thermal conditions, which may occur in winter, our results suggest condors may flap for only around two seconds per km. This remarkably low investment in flapping flight is on a par with albatrosses. In fact, albatrosses appear to flap more than condors between ( 1% and 15% of their flight time outside take-off) although it is unclear how their overall energy expenditure compares.
What is particularly striking about our findings is that all the birds we studied were immature. There was some suggestion that flight performance improved with age, but the demonstration that all birds flap so rarely shows that it is possible for even young condors to invest little energy in flying.
Condors are big by today’s standards, but 6 million years ago Argentavis magnificens, a bird with twice the condors’ wingspan dominated the Argentinian skies. It has always been assumed that these and other aerial giants used air currents to fly without flapping . The new data from the condors supports this hypothesis and shows just how far terrestrial birds can fly without needing to turn their engines on.
The main cost for large fliers in general seems to be the energy required for take-off. In our study, 75% of the flapping observed in foraging flights was related to take-off. This highlights the importance of decisions about when and where to land. On the wing, condors are confident and often fly low overhead to investigate you. On land they are ungainly, turkey-like birds that are rightly cautious. Their huge size means that take-offs are difficult and costly. But once up at least in the areas they usually fly it seems they are free to soar for hours on end.
Soaring for hours on end.MENAFN1307202001990000ID1100477197
Oncology nurses should be routinely tested for SARS-CoV-2, warn researchers – News-Medical.Net
Researchers from the NHS Foundation Trust, University of Cambridge and Cambridge Clinical Laboratories have warned that until a vaccine for severe acute respira…
Researchers from the NHS Foundation Trust, University of Cambridge and Cambridge Clinical Laboratories have warned that until a vaccine for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) becomes available, antigen and antibody testing should be carried out among oncology nurses as part of routine patient care.
The team’s study of 434 patient-facing oncology staff who worked during the peak of the coronavirus disease 2019 (COVD-19) pandemic in the UK, found that the highest seropre…
Russia stakes claim on Venus, saying it is a ‘Russian planet’ – 7NEWS.com.au
Russia plans to explore more of the planet in the coming years.
No longer confined to territories here on Earth, Russia has now staked its claim on Venus, saying it is a Russian planet.
This week, Dmitry Rogozin, head of the Russian space corporation Roscosmos, revealed that the country plans to send its own mission to Venus in addition to Venera-D, the planned joint mission with the US, the Russian state news agency TASS reported.
Rogozin was addressing reporters at the HeliRussia 2020 exhibition, an international expo of the helicopter industry in Moscow…
NASA says rocky asteroid Bennu is home to chunks of another asteroid – SlashGear
NASA has released the latest update on its OSIRI-REx mission, which involves a spacecraft that is closely orbiting a very rocky, somewhat angular asteroid calle…
NASA has released the latest update on its OSIRI-REx mission, which involves a spacecraft that is closely orbiting a very rocky, somewhat angular asteroid called Bennu. The space agency explains that Bennu is an asteroid made of rubble from other space rocks; it is the result of some massive collision in the past. Studying the rubble has revealed the presence of meteorites that originated from another — and much larger — asteroid nearby.
NASA notes in a new animated educational video that a han…
Business16 hours ago
Nikola’s chairman steps down, stock crashes following allegations of fraud – TechCrunch
Business11 hours ago
Snowflake Stock Risks a ‘Violent Selloff.’ Why One Analyst Is Worried. – Barron’s
Business17 hours ago
The COVID-19 lockdown is squeezing real estate from all sides and threatens to burst the housing and mortgage bubble – MarketWatch
National10 hours ago
Fiji Airways 737’s Epic Journey To Europe
Science22 hours ago
Asteroid 2020 SW expected near earth over Australia and New Zealand – 7NEWS.com.au
Technology24 hours ago
BMW M3, M4 ‘coffin grille’ teased ahead of unveiling – CarAdvice
Business11 hours ago
Quibi Explores Strategic Options Including Possible Sale – The Wall Street Journal
Health11 hours ago
RedState COVID Troll Streiff is Actually Bill Crews, and He Actually Works for Dr. Anthony Fauci – Daily Beast