부산대학교 도서관

Recent surveys have shown that in Albania otters occur on rivers which had been judged unsuitable in the 1980s, pointing out the need for further investigations. We assessed otter distribution on a 60 km long stretch of the River Drinos, a major tributary of the River Vjosa. Marking intensity was assessed in two seasons, spring and summer 2010, corresponding to the highest and lowest river discharge levels, respectively. Otter signs (spraints and jellies) were searched for along 300 river stretches 200 m long (sampling stations). Vegetation coverage, hydraulic pattern and human disturbance were assessed visually for the whole length of each sampling station. Both the mean number of sprainting sites and otter signs per 200 m of watercourse were higher in spring (0.81 and 2.6, respectively) than in summer (0.55 and 1.25). In spring otter signs were recorded in 118 sampling stations (39 %), while in summer, when the first 24 km of the watercourse were completely dried up, 92 sampling stations were positive for otters (31 %). Considering only the permanent river course, the variation in otter distribution was less marked (58 % vs. 51 % of 181 sampling stations). According to previous studies, the number of sprainting sites was correlated to vegetation cover, whilst variation in the hydraulic pattern of the permanent river stretch did not influence marking intensity. Our results suggest that pollution control and habitat restoration can favour otter expansion in the river plains of central and southern Albania.