The Giara Park is known above all as the place where the "Cavallini della Giara" shelters, the last wild horses in Europe. Of all the mammals living on the Giara, the Cavallino della Giara , "Equus caballus jarae" , is undoubtedly the best known. Since there are no fossil finds of horses in Sardinia, it is thought that the horse was probably introduced during the Nuraghic period or in the Punic period.
In the Middle Ages, whole herds lived on the island in the wild and some populated the island of Sant'Antioco until the end of the nineteenth century.
Characteristic for their small size, dark mantle or dark bay, manes and very long tails, they are adapted to the particular environment of the Giara, with plenty of food and water during winter and spring and shortage of the same during summer and autumn. During the winter and spring the natural depressions of the Giara, called Paulis, are filled with rainwater: the largest become large reserves and preserve the precious element until the summer. It is certainly a breathtaking experience, when they meet along the paths or hidden in the bushes, the families of horses, composed by the dominant stallion, the females and the foals, which are born in the period of February - May.
In addition to these beautiful animals, the jar is populated by wild boar, foxes, martens, hedgehogs, rabbits, hares, wild cats, martens and many others, they must also mention the many birds that live or transit, depending on the periods, on the plateau , such as the falcons and buzzards, the partridges, the great spotted woodpecker, the bee-eaters, the mallards, the storks and the knights of Italy. A special mention should be made for the "lepidurus opus Lubbocki", an archaic crustacean, which has remained unchanged for 200 million years, which lives in the paulis and which happens to spot on beautiful spring days.