Glaucidium californicum (Northern Pygmy Owl)
- Species account from the Animal Diversity Web, covering physical characteristics, food habits, reproduction, behavior, habitat, and status.
- http://animaldiversity.ummz.umich.edu/site/accounts/information/Glaucidium_californicum.html

Cactus Ferruginous Pygmy Owl (Glaucidium brasilianum cactorum)
- Photo and information about the conservation situation, in Arizona, of this endangered species of the Sonoran Desert.
- http://www.biologicaldiversity.org/swcbd/species/pygmyowl/index.html

Glaucidium californicum (formerly gnoma) Northern Pygmy Owls
- Northern Pygmy Owl - Detailed description, photos and sounds.
- http://www.owlpages.com/species/glaucidium/californicum/Default.htm