great blue, slaty, and spangled SkimmerS (Females and immature males)
Female Great Blue Skimmer, found at Beavercreek Wildlife Area on July 23, 2017.
Another view of the female Great Blue Skimmer (same individual as above). These are our largest skimmers, and they can be identified by size alone in the field. But in photos, it can be tricky to distinguish Great Blues from female Slaty Skimmers. Notice that the white shoulder patch on this Great Blue Skimmer reaches all the way to the wing base. The upper legs are mostly pale and the face is white.
For contrast, here is a teneral Slaty Skimmer. This Slaty Skimmer has a white triangular point on the top of the white patch on its thorax (just below the wing base). Great Blue Skimmers do not have this triangular point. Also, Slaty Skimmers usually have tan faces, whereas Great Blue Skimmers have white faces. Slaty Skimmers have their upper legs mostly black, and they have less black on their wingtips.
This is a female Spangled Skimmer. Note the distinctive wing stigmas. Spangled Skimmers have a half-white, half-black stigma on each wing, which is unique for this species in our area. I photographed this individual in Beavercreek on June 30th.
Another Slaty Skimmer, showing the characteristic white triangular point above the white patch on its thorax, along with its black legs and tan face.
A newly-emerged Spangled Skimmer at Grant Park. Young males look similar to the females. Again, notice the half-white and half-black stigma on each wing.