I heard but didn't spot the bird until it was distant and flying away. A small bird maybe about the size of a sparrow, looking very light color. I could only see the backside as it disappeared. Can this be identified?
I took these photos 12 years ago from Lincoln Park Zoo. I forgot to get the name back then. I checked their website recently but its not in there. What kind of bird is it? It looks to be some kind of heron.