While walking around we could hear some birds making a ruckus, but at first I couldn't see them. Then my husband pointed to the top of some trees where we could see a few Black-crowned Night herons. The nests were very difficult to find because it seems they nest in very dense-leaved trees. Nonetheless, one could certainly hear them. I couldn't get any photos of the nests or the birds in the nest because it was so shady and it was too dark for taking decent photos.
Here is a close up of a pair.