This female? osprey was hovering over the man-made lake at Berkeley Aquatic Park and diving half-way down to the lake then rising back up. Repeated this pattern several times, but didn't catch any fish.
I was really surprised to see an osprey here. Past data shows they are not commonly recorded at this area. Has anyone else seen them here? How often?
Could also be Spotted, but the pic of the spots in Paulson is from roughly the same angle, and I don't see them in mine.
Immature female heteromorph. Paulson writes that when it occurs, polymorphism in female odes is usually split into one form that resembles the male (the andromorph) and one that does not (the heteromorph). I wonder what drives this? Is there an adaptive explanation, or is this contingent on some chromosomal quirk?
More black on abdomenal segments than most pics of Tule, I think.
Since I'd forgotten about it, this was an excellent discussion on distinguishing this from the California Darner: http://www.inaturalist.org/observations/256063. I think what was confusing me there was that the face stripe diagram in Manolis only applies to the females. Male Blue-eyed Darners still have the stripe.