This is not really an aviary, it's an open-topped pen with [presumably] flight-restricted birds in it. I hope there is a small pond somewhere for the ducks [a Common Shelduck & three Red-billed Whistling Ducks] and Chilean Flamingos [which look in good condition].
I agree it really isn't an aviary, but that was the name of the exhibit. I saw no body of water in this exhibit and felt really sad for the ducks and flamingos.
So there is really a collection, open to the public, that has ducks & flamingos with no bathing/wading facilities? Over time this will lead to health as well as welfare issues.
Are you sure there isn't a pond in front of the Flamingo in the back ground?
I was in the front of the exhibit and saw nothing. I even looked around because I was surprised as well and I didn't see ANY. I was also surprised that you could get so close to them. A kids going to get their finger bitten one day.