|Thanks for the comments, Thor. I think you're right ... probably herons. Initially I thought they looked like the bird in the second photo on this link: http://www.pbcgov.com/waterutilities/wakodahatchee/anhinga.htm
but then realized they looked MORE like the second shot in this link: http://www.pbcgov.com/waterutilities/wakodahatchee/great_blue_heron.htm The ones I see are usually more blue-grey in their coloration.
Regards -- Howard
Blue Herons (2)