Andean condors spend on flapping wings less than one percent of the total flying hours — a record low for the birds. Some of these large scavengers can travel up to 172 miles, without resorting to active flight. This is the conclusion reached by the team of ornithologists track the movements of eight immature condors from Argentina. The results of their study published in the journal Proceedings of the National Academy of Sciences.
For large birds, each flapping wings is very costly from an energy point of view. This fully applies to the Andean Condor (Vultur gryphus) which inhabits the Western part of South America. The wingspan of this huge scavenger can reach three meters and a weight of fifteen pounds, making it one of the largest flying birds in the world.
Condors prefer passive form of flight: they soar for long periods of time in the sky, using the ascending air — thermal or caused by the relief. However, sometimes even these giants have to make efforts to spread her wings. A team of ornithologists headed by Emily Shepard (Emily Shepard) Swansea University decided to find out under what conditions this occurs.
2013-2018 scientists have secured eight immature condors from Argentina sensors records every stroke of the wings, the height above sea level and location. The weight of all this equipment does not exceed one percent of the total weight of a bird. Ten days later the sensor got loose and fell, and then took them to the researchers.
In total, the team managed to record data on the 235-hour flight of the condors. Most of the time birds spent on travel between roosting and feeding, as well as patrols of areas where focused livestock herds — the source of the fall.
Investigated the condors very rarely flapping the wings: they spent only 1.3 percent of the total time of flight. This is the lowest figure among all the birds: for comparison, the white storks (Ciconia Ciconia) on migration the proportion of active flight is 17 percent. From the wandering Albatross (Diomedia exulans), this figure ranges from 1.2 to 14.5 percent.
During long active flight movements amounted to 0.8 percent of the time, and during the short 8.6 per cent. Individual condors could fly from 98 to 317 minutes, never flapping wings: with regard to their speed, this corresponds to a distance of 172 kilometers.
Most often, the birds had to resort to active flight at low altitudes. In 75 percent of cases this happened during takeoff from the surface. Given the high energetic cost of flapping wings, we can assume that the condors should be very careful to choose a place for landing: this would avoid excessive waste of resources. Another situation in which the Condor flapping wings — the transition from one ascending air stream to another.
The results of the study will allow to learn more about the ecology of Andean condors and to establish a more effective protection of these rare birds. However, they are also of interest to paleontologists who try to reconstruct the lifestyle of extinct birds and pterosaurs paritala and engineers developing unmanned aerial vehicles.
Smaller relatives of the Condor — katarti black (Coragyps atratus) the vultures-the Turkey (Cathartes aura) have developed a special type of soaring flight. “Distorted” hover helps them to use a small turbulent streams at the earth’s surface and thus to be kept longer in the air.