Closely related to the vegetation, the weather and the particular geomorphology of rock crags and canyons, little mountains and watercourses, is the fauna.
The fauna, finding shelter and protection in the cavities and cracks of the rock crags and canyons of the Martín river and tributary ravines is extremely rich. Among bird specimens: wall creepers, swifts, crag martins, rock sparrows, Eurasian jackdaws, choughs, etc.
But it is the birds of prey that draw the most interest- both ecologically, and due to their high number. This is particularly true of the colony of griffon vultures ( Gyps fulvus ), which is spread out through different parts of the Cultural Park, and whos e high number make it one of the most significant agglomerates of this specimen in all Aragon. Noteworthy is also the ever-increasing number of Egyptian vultures ( Neophron percnopterus ), or white vultures, as they are known in the area. You can easily notice the majestic flight of golden eagles ( Aquila chrysaetos ), peregrines ( Falco peregrino ), kestrels ( Falco tinnunculus ) or the quick Bonelli's eagle ( Hieraaetus fasciatus )-an endangered species. Among the nocturnal birds of prey are the eagle owl ( Buho buho ), the long-eared owl ( Asio otus ), the barn owl ( Tyto alba ) and the little horned owl ( Otus scopos ), known in the area as "olivilla," who announces the night in the villages with its fluty sounds.
The scarcity of rainfall in the Park concentrates the fauna around watercourses. One of them is the Cueva Foradada reservoir, where the tamarisk wood provides suitable protection and shelter for aquatic species like the great crested grebe ( Podiceps cristatus ). Very common are also wild ducks ( Anas plathyrhynchos ), shovelers ( Anas clypeata ), teals ( Anas crecca ), garganeys ( Anas querquedula ) and gadwalls ( Anas strepera ) among other species of anatides that use resevoir's marshland during migratory periods or winter. Also noteworthy is the occasional presence of black storks ( Ciconia nigra ) and ospreys ( Pandion halieatus ), as well as the constant presence of herons flying along the Martín river looking for food. Lastly, the reservoir is also the place where cormorants ( Phalacrocórax carbo ) spend the winter.
The pinewoods provide shelter to several species: numerous little birds-attracted by insects like great tits, crested tits and other parids-which themselves attract forest birds of prey like goshawks and sparrow hawks. Among the big mammals, we can mention wild boars ( Sus scrofa ), which are able to cover long distances throughout the park, and Spanish ibexes ( Capra pyrenaica ), a growing species. In the vegetation corridors lining the river and the ravines we find foxes, badgers, stone martens, genets and, in reduced number, tiger cats ( Felis sylvestris ).
The rest of the region can be described as a semi-steppe, on undulating ground between hills and ravines, without trees and rich in bushes, like rosemary and gorses. Here, we can find many species of great cynegetic interest: partridges, rabbits, hares and little birds that adapted to this dry habitat, like crested larks and thrushes among others. Reptiles, such as lizards, ocellated lizards and ladder snakes are frequent as well.
Noteworthy are also the different species of bats in caves and cavities of the Park, especially in the Sima de San Pedro, considered by specialists as a biodiversity shelter unparalleled in Europe .