Here is a picture of a Heron in the still water that is an offshoot of the Charles River behind the Public Theater In the Brighton section of Boston. (click the more button if you are on the front page of the blog) The water is filled with algae and thus looks like Green Pea Soup. I am pretty sure this is the same Heron I saw while riding my bike a few months ago. The second pic is the Heron flying off.