In the Maremma park there are three species of wild ungulates: the wild boar, the roe deer and the fallow deer. There are other very important species from the point of view of the conservation: the wolf, the wild cat and the marten.
Between common mammals there are the fox, the badger, the stone marten, the porcupine and the hare and several species of small mammals.
A rich variety of birds are in the protected area: the Park of Maremma in fact gives hospitality to over 270 species of birds, and wetlands are an important wintering area for many species of water birds. The areas in front of the Ombrone mouth have recently become important for the wintering of numerous wild geese and cranes. In addition, many important species nest in the area, as the snowy plover, the curlew and the European roller and in 2010, thanks to a reintroduction project, the osprey is come back.
Among the birds of prey there are the peregrine falcon, the hobby, the kestrel, the buzzard, the marsh harrier and the short-toed; among the owls you can find the tawny owl, the barn owl, the owl and the scops owl. Other important bird species are the woodlark, which lives only in intact habitats, the tree creeper wich can be found only in mature woods and the green woodpecker which is a key species for the structural increase of cavities in tree trunks.