“Black-Crowned Night-Heronsof the Lake Calumet Region,Chicago, Illinois: Population Trends in a Black-Crowned Night-Heron Colony at Lake Calumet Wetlands”. Illinois Natural History Survey Bulletin 37, no. 1-6 (August 31, 2005): 109–117. Accessed May 18, 2024. https://iopn.library.illinois.edu/journals/inhs/article/view/114.