A rookery is a colony of breeding birds. Often these are man-made, and these can look like the exposed superstructure of a huge sunken pirate ship, teeming with herons, cormorants and egrets. Others are natural collections of large nests at the top of tall trees, attracting the same types of birds. I like the natural rookeries much more, and on March 20, 2016, I took some photos of Great Blue Herons at a natural “heronry” in the Danada Forest Preserve in Wheaton, Illinois. There were about 12-15 nests at the time, every one in use.