flighty

adj

1. Given to unplanned and silly ideas or actions.
2. That flies easily or often.

   “"We know that flighty birds suffer from greater risk of raptor predation, and I assume that it is useful to understand the effects of urbanization because flighty species may be more vulnerable to anthropogenic disturbance."”

3. (dated)Swift.

   “Permanent way and other checks then somewhat slowed down this flighty progress.”