Foundation for the Preservation and Protection of the Przewalski Horse - Information on this equine from Mongolia which is the sole surviving genuine wild horse in the world. theBigZoo.com: Grevy's Zebra - Facts, photos and videos of Grevy's Zebra. Back from the Brink - Article about the rescue campaign for the nearly extinct Przewalski horse. 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. 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. 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. African Wild Ass (Equus asinus) - Fact sheet from EDGE, a conservation organization that focuses specifically on threatened species that represent a significant amount of unique evolutionary history. Onager (Equus onager) - Fact sheet from EDGE, a conservation organization that focuses specifically on threatened species that represent a significant amount of unique evolutionary history. Sable Island Photographs - Photographs of some of the 300 free-roaming feral horses that live on this island off Nova Scotia. Grevy's Zebra (Equus grevyi) - Fact sheet from EDGE on this endangered species from East Africa. Mountain Zebra (Equus zebra) - Fact sheet from EDGE on this endangered species from Namibia and South Africa. The Donkey - Research project on Equus asinus by Kelsey Wells at the University of Wisconsin-LaCrosse. Equine and Animal Cognition Reference Database - A literature database for researchers in the field of animal cognition and equine science. African Wild Ass: Equus africanus - Photographs, videos and information from ARKive including classification, status, description, range, habitat, biology, threats and conservation. Przewalski's Horse: Equus ferus przewalskii - Many videos and photographs with details of classification, status, description, range, habitat, biology, threats and conservation. Grevy’s Zebra: Equus grevyi - Many videos and photographs with details of classification, status, description, range, habitat, biology, threats and conservation. Asiatic Wild Ass: Equus hemionus - Many videos and photographs with details of classification, status, description, range, habitat, biology, threats and conservation. Plains Zebra: Equus quagga - Photographs, videos and information from ARKive including classification, status, description, range, habitat, biology, threats and conservation. Quagga: Equus quagga quagga - Photographs and information from ARKive on this species which was endemic to South Africa but is now extinct. Mountain Zebra: Equus zebra - Photographs, videos and information from ARKive including classification, status, description, range, habitat, biology, threats and conservation. Zebra - Factsheet with photographs, physical characteristics, habitat, behavior, diet, predators and threats. University of Michigan Museum of Zoology - Many details and links to information about the family Equidae. Grevy's Zebra - Factsheet with photographs, physical characteristics, habitat, behavior, diet, predators and threats. National Park Service: Assateague's Wild Horses - Discusses the feral horses of Assateague Island, Maryland, USA.