OTTER (LUTRA LUTRA) WINTER PREDATION ON CARP PONDS

摘要

The majority of problems associated with otter predation on fishponds arise in winter months, especially during the period when ponds are ice-covered. The majority of studies of otter diet at fishponds is based on analyses of faecal samples (spraints)and is concentrated mostly on ponds stocked with younger carp (Kloskowski, 1999, Roche, 2001, Kortan et al. 2007). However, these studies do not reveal the extent of large individuals of commercial fish species in otter diet because they rely on spraintanalysis, a method which underestimates (or fails to record) the proportion of large fish. Previous study showed that the size of fish eaten by otters as being assessed from uneaten fish remains found near fishponds differed considerably from that determined by spraint analyses (Adamek et al, 1999, 2003).