Thought maybe your site could use this male Walker's Darner. I will add a few notes about this interesting species.

Male Aeshna walkeri in the Santa Cruz mountains spend the day working shady stream banks in search of females. They favor steep banks with lots of exposed tree roots and dark crevices. (Perhaps their eyes are adapted for low light?) Early in the season they will patrol and feed like other darners, but once they go into breeding mode they spend most of the day searching for females, not feeding or resting until late afternoon, when they disappear into the trees.

This shot shows some of the diagnostic features of the male Walker’s: whitish face with no blue, green or yellow; eyes mostly brown with gray below; thoracic stripes straight, all white; tenth abdominal segment all black; pterostigma black; short spine on the cerci.

Other notes: Presumably, receptive females would be found in the dark places where the males search, but I have never seen one there. I have, however, seen females solo ovipositing late in the day here (not guarded or in tandem). The 8/8 date of this photo was my first sighting this year, although they might have showed up as much as two weeks earlier. I will report the last date they can be found at this site, expected to be some time in October, although they are known to fly in this area into November. As of late September the stream is at a low trickle, not dry, with occasional standing pools where females oviposit. The tree cover consists mainly of red alder, sycamore and willow. I will edit these notes as I learn more about this species in the Bay Area.