that's just what I was wondering. I think it must be a black-crowned night heron (I thought yellow-crowned first because it looks like it has the head plumes, but there are no wild yellow-crowns in Hawaii and I don't think the zoo has them). I also see two mallards (left and right) and a black swan. But what's the black and white thing on the water to the back, in front of the rocks? I can't make it out.
Yes, a Comb Duck and Black-crowned Night Heron. The Comb Duck is part of the exhibit, the Heron is a wild bird. There are better photos of both in the gallery.
