A Flash of Red - The Northern Cardinal
- Brief narrative and photos of Cardinalis cardinalis.
- http://birding.about.com/library/weekly/aa121397.htm

Pyrrhuloxia (Cardinalis sinuatus )
- Photos, range, physical traits, and natural history.
- http://animaldiversity.ummz.umich.edu/site/accounts/information/Cardinalis_sinuatus.html

Cardinalis cardinalis (Northern Cardinal)
- Scientific classification, range, physical traits, and natural history.
- http://animaldiversity.ummz.umich.edu/site/accounts/information/Cardinalis_cardinalis.html

Northern Cardinal (Cardinalis cardinalis)
- Photo, range maps, and facts about this bird's diet and habitat. Includes a sound file.
- http://www.nenature.com/NorthernCardinal.htm

Pyrrhuloxia (Cardinalis sinuatus)
- Photo of this species, also known as the Gray Cardinal.
- http://www.nps.gov/whsa/bird%20list/pyrrhuloxia.htm

Pyrrhuloxia - The Gray Cardinal (Cardinalis sinuatus)
- Describes this bird's physical appearance, habitat, and nesting. Includes photos.
- http://aviary.owls.com/pyrrhuloxia/pyrrhuloxia.html