Two American Kestrel males in Green-Wood.
Hunting must be good here, because I’ve seen kestrels in this area for years. There are some great perches, with meadow below. When I was there Saturday, both Spot-winged and Wandering Gliders, the orange-y dragonflies that seem to be constantly in the air, were flying at eye-level. Kestrels eat dragonflies. Crunchy on the outside, gooey on the inside — one supposes.
Rare to see a Wandering Glider perched. They’re on the wing most of the time. The Flying Dutchman of dragonflies.
Spot-winged Glider. They don’t perch much either, but perhaps a little bit more than the Wandering. Fairly similar, but with small dark patches at the hindwing base.
These smudges can be seen in flight…
Backyard and Beyond 
We are seeing many large blue green dragonflies dead on the sidewalks of the upper East Side. Their wings are close to 5″ across and they are always upside down. Do you have any idea what is happening?
I don’t. Sounds like Common Green Darners (Anax junius). They’re migratory and sometimes gather in large numbers–although it seems a bit early for that.