Ectopistes migratorius
- Maggie Brown provides information on the Passenger Pigeon, its classification, habitat, adaptation, nutrition, reproduction, human uses and extinction.
- http://acadweb.uwlax.edu/07Spring/SAH/BIO203/brown_magg/

The Passenger Pigeon
- A different view of the demise of the passenger pigeon, which argues that the bird's way of life also doomed it.
- http://www.press.uchicago.edu/Misc/Chicago/779939pass.html

History of My Passenger Pigeon
- Extensive information about the extinct birds including newspaper articles, museum information, artwork, films, and links.
- http://www.ulala.org/P_Pigeon/George.html

Extinction: The Story of the Passenger Pigeon
- Brief history of the events leading up to the extinction.
- http://www.eco-action.org/dt/pigeon.html

Encyclopedia Smithsonian: Passenger Pigeon
- Summary of the biology and extinction of the species, including a description of their exhibit of Martha, the stuffed remains of the last living specimen of the species.
- http://www.si.edu/resource/faq/nmnh/passpig.htm

Extinction of the American Passenger Pigeon: The True Story
- Essay by Edward Howe Forbush written in 1917.
- http://www.wildbirds.org/apidesay.htm

Passenger Pigeon Society
- Informal society dedicated to the preservation of the memory of the extinct Ectopistes migratorius. Site includes membership sign-up, an extinct bird mailing list, and links.
- http://www.passengerpigeon.org/