The Paiva river is considered one of the cleanest rivers in Europe, it is possible to find along its valley a great diversity of habitats, fauna and flora. The extensive areas of forest harbor diverse avifauna, as the stunning bullfinch, the great spotted woodpecker, the goldfinch or the common buzzard. By Paiva river and its tributaries we can already notice riparian birds as the sleek white-throated dipper, the common kingfisher or the real-heron. In the wild waters of the Paiva in habit several species of fish, such as trout, the portuguese nase and the iberian chub. Along the Paiva river can be observed several dragonflies, as the western spectre, the golden-ringed dragonfly, the keeled skimmer, the orange-spotted emerald dragonfly or the river cruisers dragonfly, species considered very rare in Europe. Endemic to the region, the pedunculated anarrhinum is present in Paiva valley, in slopes and rocky places. In the mountainous areas of the valley, such as the Montemuro mountain and the Gralheira mountain chain, two enigmatic species survive in the territory: the iberian-wolf and the majestic snub-nosed viper.