This species is perhaps the most widely distributed dragonfly in the world, breeding on every continent except Antarctica and western Europe, and sometimes found thousands of km from land over the open ocean.   It's identified by the yellowish tapered abdomen, plain gray thorax, large triangular hindwings (visible in two of the pictures of the resting individuals), and striking yellow face.   Occasionally they feed in swarms, but as with many dragonflies the males patrol and defend territories.   They seem to perch rarely but frequently hover, which (along with long lenses and quick, modern autofocus) makes flight shots like these possible.   More wandering glider images are here.
            A close relative of the wandering glider is the similar spot-winged glider, which has the same general shape and habits.