Observations on the predation behaviour of the otter Lutra lutra in NE Spain

Adult and sub-adult otters Lutra lutra (Linnaeus, 1758) caugh and consumed 3.36 prey (fish) per hour (n=32 captures). This represents 273.8 g of wet mass/h of activity outside the rest sites. (10.5-13.1% of the day) and it is enough to get their daily needs. Otters ate the pray without hiding on average (n=93) 0.46 m from the bank (up to 3.9 m) and 0.25 m above water level (up to 2.05 m). Prey weighing less than 150-200 g were consumed entirely, for this reason prey remains are very rare (except large trout, American crayfish and gravide cyprond females). Unpleasant tasting or toxic parts and sharp or wide parts of the bones, scales, teeth, claws, heads or leggs in large prey were not eaten.