Aeshnids, like these blue-eyed darners (relatives of the equally lovely common green darner , are extremely specialized for nearly continuous flight, and spend hours at a time on the wing.   The blue males patrol territories around standing water, watching for the greenish females and for prey.   Occasionally they will hover in one spot and I was able to get images of several patrolling males in early October, at the San Jacinto Wildlife Area near Riverside, California (modern autofocus equipment can work wonders -- these males were hovering but nevertheless were in constant motion).  More images of these dragonflies are on this page.
            Occasionally one can find cooperative individuals that allow extreme close-ups, as in some of the images on this page.
            (Another binomial for this species is Aeshna multicolor.)