A recent study shows that the Andean condor, which weighs up to 15 kg (33 lb), can soar more than 100 miles (160 km) without flapping its wings. The research, led by Dr. Sergio Lambertucci of the Universidad Nacional del Comahue in Argentina and Professor Emily Shepard of Swansea University, indicates that the Andean condor only flaps its wings 1% of the time in flight.
Different species of birds flap their wings in different ways. Some flap their wings continuously to stay in the air, while others dive and glide. The most impressive of them all is the soaring birds, which include the albatross, eagles, hawks, and of course, the Andean condor.
The Andean condor lives in the Andes mountains along South America’s Pacific coast. It has a wingspan of roughly 11ft (3.3m) and feeds on large carrion (the decaying flesh of dead animals), including deer, sheep, and cow, though sometimes they eat smaller animals too.
The team set out to investigate how a heavyweight like the Andean condor manages to fly. They used high-tech flight-recorders to track how often the birds made turns in the air or flapped their wings as they soared around, searching for food.
The data showed that 75% of all flapping occurred when the Andean condor was taking off. Once the condor is in the air, it pursued updrafts and rising thermals allowing it to gain and maintain altitude so that it can soar for a long time. One of the birds the team tracked managed to soar 100 miles for five hours without flapping.
Dr. Hannah Williams, the study’s author, said:
Watching birds from kites to eagles fly, you might wonder if they ever flap. This question is important, because, by the time birds are as big as condors, theory tells us they are dependent on soaring to get around. Our results revealed the amount the birds flapped didn’t change substantially with the weather. This suggests that decisions about when and where to land are crucial, as not only do condors need to be able to take off again, but unnecessary landings will add significantly to their overall flight costs.
Since the studied birds were not fully matured, these energy-saving techniques of soaring are most likely adopted by the condors at a young age.
Dr. Lambertucc added:
This is a critical time as birds need to find rising air to avoid an unplanned landing. These risks are higher when moving between thermal updrafts. 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. This is a nice example of where the behavior of the birds can provide insight into the behavior of the air.
The team published the findings on July 13 in the journal Proceedings of the National Academy of Sciences.
