In this study, both habitat use analysis by rumen contents of Eurasian river otter (Lutra lutra) were
carried out to investigate the preference of habitat environment and diet using their fecal samples. As the target
sites, two streams (the Naechon-cheon and the Koonup-cheon) were selected in the upstream of the Hongcheon
river, Hongcheon County, Gangwon Province. A total of 478 track samples (e.g., feces, scent and footprint) were
found during the survey periods (May to November, 2009 and November, 2010). The dominant points, where the
tracks of river otters were observed, were areas with the low depth(0.5-1m) and the slow flow velocity (5m/sec).
Also, both rocks and rock-beds were preferred but artificial facilities were avoided. This ecological study of river
otters using habitat use analysis and diet analysis by rumen contents will be useful fundamental information to
conserve the river otter populations, and to protect their habitats.