Widow Dragonfly (Libellula luctuosa)
(Identification courtesy of my son Sam, full-time med student, part-time Herpetologist and naturalist)

Now strictly speaking, I'm not sure these next two shots belong in a "Zoo" gallery, but that's where they shot, in the swamp exhibit. I have always been fascinated by these creatures, and photograph them whenever there's an opportunity. Canon 100-400 at 400 mm, ISO 100, f/5.6, 1/320 second (hand-held).