Chicago Flower and Garden Show - General information for flower show held in March.

Chicago Ornithological Society - A modern birding club that promotes the scientific and educational aspects of ornithology; image galleries, education activities, meetings and programs, rare bird alerts, media library and membership information.

Chicago Department of Environment - Official city site offers information on air quality, energy, the natural environment, shoreline projects, property cleanup and redevelopment, environmental public health and safety, and recycling.

Down the Drain, Chicago's Sewers - Provides a history of the sewer system.

Chicago River - Chicago Department of Environment's comprehensive website on the history, recreational uses, and cleanup projects of the Chicago River.

Chicago Audubon Society - Provides information on activities, events, bird count results, newsletters, membership information and educational opportunities.

Hyde Park Parakeets - Provides nesting maps, photographs, scientific abstracts and newspaper articles on parakeets, including feral monk parakeets.