It has also been known to sound an alarm call when hawks or other dangers are near , and smaller birds often recognize this call and hide themselves away accordingly .
It has also been known to sound an `` alarm call '' when hawks or other dangers are near , and smaller birds often know this call and hide themselves away accordingly .
A 2005 study by Sankar Chatterjee suggested that the wings of Microraptor functioned like a split-level `` biplane '' , and that it likely employed a style of gliding , in which it would launch from a perch and swoop downward in a ` U ' shaped curve , then lift again to land on another tree , with the tail and hind wings helping to control its position and speed .