Potravná ekológia vydry riečnej (Lutra lutra) v CHKO Kysuce [Food ecology of the European otter (Lutra lutra) in the Kysuce Protected Landscape Area (NW-Slovakia)]
Ján Koščo, Ján Korňan
Altogether 350 otter spraints from the Kysuce river basin in the Kysuce Protected Landscape Area (PLA) were collected betwen January and August in 1991 and 1992. Undigested remains were analysed and the frequencies of occurrence were determined. The amount of each item was also recorded. The most important prey items in the spraints were fishes. The frequency of fish remains was 91,8%, bones of frogs were found in 34.7% of samples. Crayfish represented another important prey item (18,4 %). Remnants of mammals were found in 16.3% of samples, those of birds in 8.2% and those of reptiles and molluscs in 4.1%. The dominant fish species were chub (Leuciscus cephalus) – 59.3%. and brown trout (Salmo trutta m. fario) – 24.1%. The prevailing size of the fishes in the age 0+ and 1+ was 100–200 mm, The aquatic habitats and natural conditions of Kysuce PLA offer a sufficient food supply to satisfy the trophic requirements of the river otter living in that region.