Distribution, Density, Diet and Habitat Use of the Otter in Relation to Land Use in the Araglin Valley, Southern Ireland

摘要: The distribution, density, diet and habitat use of the otter (Lutra lutra) were examined in Araglin Valley, counties Cork, Tipperary Waterford. Otter signs (tracks, spraints, anal secretions, holts, etc.) environmental conditions (river depth, river width, flow regime, vegetation cover, recorded at 112 sites across three types (agriculture, moorland forestry) valley. Three definite home range boundaries delineated by high levels sprainting scraping, results indicated presence six or seven otters. Significant correlations between lying-up availability but no trends found cover velocity. A positive relationship was spraints agriculture habitats, a negative correlation forested sites. Percentage frequency occurrence, relative percentage frequency, bulk (Sc%) calculated for twelve food categories based on seasonal data sets. Fish (mainly salmonids eels) predominant category each season (Sc% = 70.03). Other significant included small quantities mammals, birds, frogs crayfish (both February March). Considerable variation revealed related to differences among different location range. In 3, fish prey relatively scarce, while birds more important. contrast, important ranges 1 2. trophic niche breadth otter, evaluated using Levin's index, varied little throughout study period, with peak spring/early summer minimum value late autumn (October-November). Paola Ottino Paul Giller (corresponding