What if someone says a bird can fly for up to 10 months continuously in a year? Would you believe it? Yes, now you have to as there are enough evidences to prove it correct.
Common swift is a bird that can be seen in Europe, West Asia and Northern India with an average lifespan of 20 years. And it is said that its total flight distance can be equaled to the seven round trips between moon and earth
How common swift comes to consideration with this news is like this: although you have heard of birds in flight for long period of months such as alpine swifts and frigate birds, common swifts set the record of longest flying phase of 10- month flight phase.
Even though there were various beliefs about swifts staying airborne for a considerable long time, there were not enough proofs to confirm it. But researchers from Lund university of Sweden could present evidences on this matter and published in Cell Press journal Current Biology.
According to the observations done about these common swifts, these birds leave the breeding site (ground) in August and migrate to Central African rainforests flying across the West Africa. And they will not be landing on ground until the next breeding seasons after 10 months.
In order to prove this, researchers developed a new type of micro data logger to monitor birds’ flight activities. Later on it was improved with light sensors for track the geo location as well. With 19 data loggers attached to common swifts they could observe what those loggers logged when the swifts were recaptured.
According to the logs, 99% of their time was spent in flight during this non breeding period. But some of the swifts rested in some points of the journey yet that period was also really a short time period compared to the time they spend in the fly. A reason for them not landing is that they have long wings with short legs which make it difficult to take off from flat surface.
How do they save energy and sleep? They are gliding in upward currents of warm air and that is why they fly lower than at night. And about the sleep, they might sleep while gliding.