The Oasi WWF Lago di Alviano is an Important Birding Area (IBA) between Umbria and Lazio regions. The lake of Alviano was created by the construction of a dam on the Tiber river in 1963 by ENEL (National Electric Power Company) for hydroelectric power production. This shallow reservoir has since turned into an interesting wetland, becoming a hotspot for thousands of migratory birds as well as an important nesting area. Protected since 1978, from 1990 WWF manages the Reserve and provides visitors access by through two boardwalks with birdwatching hides. A variety of habitats are protected within the reserve: riparian woodland, reedbeds, marsh, and the shallow lake, a total of 900 ha.
There are two itineraries that run through the Oasi, marked with explanatory panels and several observing huts perfect for birdwatching. Both are at the north end of the lake, at Madonna del Porto.
The first one (Sentiero Natura) is a 1,5 km circular footpath also practicable for disabled. There are 6 hides and a tower allows visitors to watch birds without disturbing them in different habitats. At the Aula Verde (two level hide) there is a telescope to help visitors on their observations.
The second path (Vecchio Sentiero) has been left as natural as possible without explanation panels and less hides, 2,5 kms than run into the riparian woodland beside the Tiber river. Practicable with some difficulties on winter due to the rain and the nearness of the river, gumboots can be useful!
More than 150 bird species have been recorded. Between November and March the lake hosts high concentrations of ducks and other waterfowl, including mallards, gadwalls, pochards, shovelers, common teals, ferruginous pochards, northern pintail and geese; grey herons, little and great white egrets, and bitterns; grebes, kingfisher, coot and moorhens are sedentary species and breed every spring in the reserve.
During migration time the water meadow areas host black-necked, godwit, spotted redshank, curlew and many others sandpipers.
Spring and summer is the time for red warbler, little bittern, purple heron and squacco heron.
Raptors are easy to be seen when flying over the wetland looking for a prey. Marsh harriers, black kites, peregrine falcon, buzzards are seen regularly and ospreys on migration every year.
The heron nest colony
Three years ago a group of grey herons formed a colony on an island where trees were big enough to become the sitting of their nests. Other heron species arrived to the colony for breedding. Little egrets, squacco and night herons and cattle egrets form a noisy and highly active colony from February until August.
Not just birds….
Walking through the paths of the reserve mammals tracks are easy to see. Wildboars and foxes live in the forest as well as badgers and crested porcupines.
Visiting the Oasi on spring and summer visitors can run into reptiles and amphibians, wall lizards and snakes as ringed snake swimming in the ponds while looking for frogs.