We have a 1/2 mile trail on the property and of late it's has been spattered with discarded bird eggs, large blue-green ones to be exact. The eggs aren't as big as our chicken eggs, but they aren't small like a robin egg either. Our friend Cary happens to be an avid birder so we were hoping that she'd be able to identify the eggs and the birds that produced them. Based on the size of the eggs and a description of their call (something similar to a fox barking), Cary told us they were probably herons. She sent us a link to http://www.allaboutbirds.org/ and after listening to a few calls we narrowed the birds down to Black Crowned Night Herons which make a barking call and are nocturnal. We've only heard the calls around dark so her identification fit perfectly.
We love our chickens and will post more about them later, but this discovery was too exciting not to share.