Road traffic is an increasing cause of wildlife mortality, both in terms of the expansion of transport infrastructures as well as of the increasing number of circulating vehicles. In the United States the wildlife mortality due to collisions with vehicles has been estimated around one million vertebrates per day (Laslo, 1987) and the data available about Europe seem to confirm an alarming situation. In fact, in Europe it has been estimated that between 10 and 100 million birds and mammals are killed on the roads each year. According to a new computational procedure developed in Sweden, for each 10.000 km travelled by a vehicle one bird is killed. On a road with a traffic of 300 vehicles per hour, an amphibian has a probability of 18% to be killed, and a micromammal of 10%. Road kills cause 1-4% of the mortality of common species, but this figure may reach 40% for the most sensitive species (Guccione er oth, 2008).
For each Italian Province it has been estimated that at least 15.000 animals are killed on the roads each year, however this number is purely indicative because the phenomenon is not yet accurately and systematically monitored. In the last years the number of studies on the impact of the transport infrastructures on wildlife has increased but we are still far from the definition of an effective monitoring and management of the issue. So far surveys have been developed only locally and/or limited to specific groups of vertebrates.
Concerning the project areas, the available data refer only to the damages reported or compensated by each Province administration according to the regulations in force. In the period 2001-2008 in the Provinces of Siena and Grosseto 400 car accidents caused by wild animals have been reported and in Umbria Region 1.341, with an increase over the years. In Province of Pesaro-Urbino, in the period 2000-2005, the reported car accidents caused by wild animals fauna were 646. The most frequently involved species were Roe deer, Wild boars, followed by Fallow deer, Red deer, badgers, porcupines and foxes but also kills of wolves, mouflons, wild cats, nocturnal raptors and other bird species were recorded.
These data are to be considered partial and underestimated because not all the accidents are reported and those reported regard mainly, if not only, the collisions with wild ungulates. Moreover, even where the collisions are reported there are no regularly updated databases that allow a precise quantification of the phenomenon.
As a conclusion, today it is not possible to have an accurate estimate of the wildlife mortality due to road traffic in the project areas.
In this fragmented context the LIFE STRADE project intends to promote a thorough analysis of this phenomenon, necessary as a basis to experiment possible mitigation measures.