Diets of Cape clawless otters at two South African coastal localities

<span style="font-family: CharterBdBT; font-size: xx-small;"><span style="font-family: CharterBdBT; font-size: xx-small;"><span style="font-family: CharterBdBT; font-size: xx-small;"><p>The diet of the Cape clawless otter</p></span></span></span><em><span style="font-family: CharterBdBT-NormalItalic; font-size: xx-small;"><em><span style="font-family: CharterBdBT-NormalItalic; font-size: xx-small;">Aonyx capensis </span></em></span></em><span style="font-family: CharterBdBT; font-size: xx-small;"><span style="font-family: CharterBdBT; font-size: xx-small;">was investigated at the Dwessa Nature Reserve <span style="font-family: CharterBdBT; font-size: xx-small;">and Mkambati Nature </span></span></span><strong><span style="font-family: CharterBdBT-Bold; font-size: xx-small;"><strong><span style="font-family: CharterBdBT-Bold; font-size: xx-small;">Reserve </span></strong></span></strong><span style="font-family: CharterBdBT; font-size: xx-small;"><span style="font-family: CharterBdBT; font-size: xx-small;">on the Wild Coast, Eastern Cape Province, South Africa. Their diet was more varied at Mkambati (15 prey species) than Dwessa (7 species). In terms of </span></span><span style="font-family: CharterBdBT; font-size: xx-small;"><span style="font-family: CharterBdBT; font-size: xx-small;"><span style="font-family: CharterBdBT; font-size: xx-small;">percentage relative frequency of occurrence, the spiny lobster </span></span></span><em><span style="font-family: CharterBdBT-NormalItalic; font-size: xx-small;"><em><span style="font-family: CharterBdBT-NormalItalic; font-size: xx-small;">Panulirus homarus  </span></em></span></em><span style="font-family: CharterBdBT; font-size: xx-small;"><span style="font-family: CharterBdBT; font-size: xx-small;">was found to be the most common prey item at both Mkambati (37.93%) and at Dwessa (35.21%), followed <span style="font-family: CharterBdBT; font-size: xx-small;"><span style="font-family: CharterBdBT; font-size: xx-small;">by fish (31.03% and 36.62%, respectively), crab (22.41% and 19.72%) and molluscs (3.11% and 4.23%). No significant differences were found in spraint dry masses between sites (15.10 g <span style="font-family: CharterBdBT; font-size: xx-small;"><span style="font-family: CharterBdBT; font-size: xx-small;">vs 17.95 g) or between masses of the diet categories for the two regions, but, when converted to ‘fresh’ mass, mean spraint mass was significantly lower at Mkambati than Dwessa (108.08 g and 135.73 g, respectively). When diet categories were compared using ANOVA, only fish were <span style="font-family: CharterBdBT; font-size: xx-small;"><span style="font-family: CharterBdBT; font-size: xx-small;">found to be significantly different when expressed as fresh mass. Spiny lobster mandibles collected from spraints were used to estimate otter prey size preferences by comparing with <span style="font-family: CharterBdBT; font-size: xx-small;">wild-caught lobster dimensions (ANCOVA, paired </span></span></span><em><span style="font-family: CharterBdBT-NormalItalic; font-size: xx-small;"><em><span style="font-family: CharterBdBT-NormalItalic; font-size: xx-small;">t </span></em></span></em><span style="font-family: CharterBdBT; font-size: xx-small;"><span style="font-family: CharterBdBT; font-size: xx-small;">-tests, correlation and regression). Otters </span><span style="font-family: CharterBdBT; font-size: xx-small;"><span style="font-family: CharterBdBT; font-size: xx-small;"><p><span style="font-family: CharterBdBT; font-size: xx-small;">ate spiny lobsters with carapace lengths between 39.5 and 72.0 mm CL. Differences in diet were compared with published data from elsewhere. Lobster and fish are relatively abundant within these reserves, suggesting prey availability rather than selective feeding influenced diet.</span></p></span></span></span></span></span></span></span></span></span>