Frigates - unique birds. They possess very weak legs and usually sit only on trees, it is easier to take off. But in the air in the frigates of competitors no - powerful wings and a small weight make a bird with a real maritime pirate: for example, it can catch a bat in the air or take prey from another born. Three quarters of the life of the frigates are carried out in the air, so it is not surprising that they attract so much attention from the ornithologists.
For a long time, experts could only build assumptions on the expense of how a living being can manage so long to touch the Earth. Recently, experts have finally wanted to find out this issue once and for all and organized a study for some time watching the selected individuals of frigates. Special sensors helped them in this, tracking not only the location of birds, but also the ambient temperature, the pressure level and even the heart rate of the feathery.
What was the surprise of scientists when they saw that young frigates could carry out in flight up to two months - much longer than previously predicted. Moreover, at different times, the height of the flight of birds varied from 30 to 2000 meters above sea level.
Further decoding of temperature indicators explained how the birds manage to spend a lot of time in the air. During the daytime, the frigates rise to a height of several kilometers using the rising streams of heated air. The large area of the wing gives these birds a huge advantage: they may not make a single wave for several hours, which indicates information from the cardiac rhythm sensor. Under the evening, the frigates slowly along the spiral trajectory are lowered together with the cooled air closer to the water. With the onset of the morning the cycle is repeated anew.
One of the frigates was in the air for 48 days, "wound up" every day a distance of hundreds of kilometers. Moreover, cardiac rhythm sensors have shown that this type of birds can sleep right in the air during a relaxing airflow. Scientists believe that the young birds are particularly endured in the air to two months.