Photograph taken near edge of Pescadero estuary, a few feet from where this post was shot, which I'm (perhaps cavalierly) assuming is the same species. Although this photo was take 50 days later, the remains of the nearby sea lion carcass were still discernible...though much reduced.

Again, wish I had a more detailed shot, but as least you can make out some of the wing venation details and also see the long (right) arista of the (female?) at the bottom of the double piggy-back ride. (I wonder if she's an albino or if that's sexual color dimorphism?) She also appears to have a rather swollen head (literally...not just because she finds herself so popular :-).

As before, hoping cognoscenti will let me know if I haven't got a Clusiidae '-)