The Eurasian otter Lutra lutra (Linnaeus, 1758) in Portugal

Lutra lutra (Linnaeus, 1758) en Portugal Lutra lutra (Linnaeus, 1758) igaraba eurasiarra Portugalen ABSTRACT Eurasian otters Lutra lutra (Linnaeus, 1758) are known to occur in Portugal since historical times but only in 1995 a national survey confirmed the species' broad distribution.Since then, studies and projects conducted in different aquatic environments indicate the existence of a healthy population, the availability of vegetation cover, water and prey being the major factors explaining otter presence.Spraint analyses showed that fish, amphibians and American crayfish form the bulk of otter diet.Due to increasing knowledge about the species ecology and distribution, in 2005, otter status was changed, from "Insufficiently Known" to "Least Concern".Recent main lines of investigation have become increasingly threat specific and include: otter use of reservoirs, man-otter conflicts (fish farming), otters and non-native species interactions (prevalence in otter diet; competition with American mink) and otters and antimicrobial resistant bacteria.Destruction of the riparian vegetation commonly associated with dam construction, river regulation, agricultural expansion, gravel and sand extraction, as well as the development of tourism in, costal and wetland areas are still potential threats to otter populations.Overall, in the near future otters seem safe from major disrupting settings but otter conservation and effective management are still an important issues.This is especially relevant in the Iberian Peninsula, as climate changes are expected to reduce suitable otter habitats.Knowledge gaps and future research needs are also addressed in this chapter.