Effects of extensive fishpond management and human disturbance factors on Eurasian otter (Lutra lutra L. 1758) populations in Eastern Europe

Wetland losses related to human activities in the past decades have caused heavy decline in the population of the Eurasian otter (Lutra lutra Linnaeus) throughout Europe. As otters are often used as flagship species for wetland conservation programmes, the understanding of their response to human disturbance and environmental factors is essential to fine-tune conservation tools for managing artificial water bodies. In this study we estimate which wetland characteristics and human factors to what extent drive the spatial distribution of otters. We investigated factors related to the habitat selection of Eurasian otters between December 2004 and January 2007 on 31 fishponds in the Hortobagy National Park, Eastern Hungary. We have shown that otter habitat selection is primarily governed by both disturbance-related characteristics and vegetation properties of fishponds, and not by humans. Moreover, we did not find the effects of artificial fisheries inputs or hunting pressures. Fishponds far from human settlements with large reed islands and dykes with trees are the key habitats for Eurasian otters. However, the presence of adjacent forests and grazing areas negatively affect the otter sign densities in fishponds.