Animal Web: Equidae
Information on the Mountain, Grevy's and Plains Zebra.
http://www.animalweb.com/animalworld/family-equidae.asp

theBigZoo.com: Grevy's Zebra
Facts, photos and videos of Grevy's Zebra.
http://www.thebigzoo.com/Animals/Grevys_Zebra.asp

Wild Horses -- an American Romance
History and current state of wild horses in America.
http://net.unl.edu/artsFeat/wildhorses/

University of Michigan Museum of Zoology
Many details and links to information about the family Equidae.
http://animaldiversity.ummz.umich.edu/chordata/mammalia/perissodactyla/equidae.html

Back from the Brink
Article about the rescue campaign for the nearly extinct Przewalski horse.
http://www.gluckman.com/MongoHorse.html

The Quagga Project
Attempts to breed through selection a population of Plains Zebras, which in its external appearance, and possibly genetically as well, will be closer, if not identical to the former population known as "Quagga", which was exterminated during the second half of the 19th century.
http://www.quaggaproject.org/

Sable Island Horses
Describes the wild horses of Sable Island, Canada.
http://www.greenhorsesociety.com/Horses/Horses.htm

International Museum of the Horse: Horse Breeds of the World
History and breed characteristics organized by continent and name.
http://www.imh.org/museum/breeds.php?pageid=8

National Park Service: Assateague's Wild Horses
Discusses the feral horses of Assateague Island, Maryland, USA.
http://www.nps.gov/archive/asis/horses.htm

Western Horse: Equus occidentalis
Factsheet on this horse, also known as the Western Quagga, which became extinct about 11,000 years ago.
http://www.bbc.co.uk/nature/wildfacts/factfiles/3054.shtml

Propalaeotherium: Propalaeotherium parvulum
Factsheet on this extinct species, with a photograph of what it would have looked like.
http://www.bbc.co.uk/nature/wildfacts/factfiles/434.shtml

Plains Zebra: Equus burchellii
Factsheet on this mammal from East Africa, its description, distribution and biology, with several photographs.
http://www.bbc.co.uk/nature/wildfacts/factfiles/628.shtml

Asiatic Ass: Equus hermionus
Factsheet on this wild relative of the domestic donkey, its description, distribution and biology, with several photographs.
http://www.bbc.co.uk/nature/wildfacts/factfiles/626.shtml

African Ass: Equus africanus
Factsheet on this critically endangered species, its description, behavior and reproduction.
http://www.bbc.co.uk/nature/wildfacts/factfiles/625.shtml

Equus caballus: The Horse
Research project by Kelsey Posta on this domesticated mammal including its classification, habitat, reproduction, adaptations, nutrition and interactions with other species.
http://bioweb.uwlax.edu/bio203/s2008/posta_kels/

Grevy's Zebra: Equus grevyi
Research project by Alexandra Price on this, the largest of the zebra species, including its history, habitat, reproduction, adaptations, nutrition and classification.
http://bioweb.uwlax.edu/bio203/s2008/price_alex/