Impact of two forest roads upon wildlife after a road pavement change in a coastal area in the center of Portugal

The impact of traffic on wild vertebrate populations in two forest roads was assessed. These two roads cross the Perímetro Florestal das Dunas e Pinhais de Mira, located in the littoral centre of Portugal. One of the roads was paved with asphalt. The other was already partially paved but later on it became completely paved with asphalt. These new pavements considerably contributed to the increase of traffic in these roads. Between September 1996 and August 1997 the one-way transepts (13 km of forest roads) were reviewed 10 times a month using a vehicle at a 20-40 Km/hour speed. Vertebrate road casualties (n = 831) included 46 identified species and 7 nonidentified individuals. Amphibians presented the highest values for road casualties (81%), followed by birds (9%), reptiles (6%) and mammals (4%). The highest mortality rates occurred between November and March and in the 2nd, 5th and 7th kilometres. Amphibians were the most affected group. The common toad Bufo bufo, presented the highest mortality values (49%), constituting nearly half the road casualties registered during the study period. In a short-term period, this mortality might produce negative effects upon longevity and reproduction of some vertebrate species.