Study of otter (Lutra lutra) Distribution Along Jajrood River

The Eurasian otter (Lutra lutra) is a semi-aquatic mammal from Mustelidae family. It is recognized as one of the top predators in freshwater systems, and thus has the potential to play an important role in the functioning of these systems. There are only 2 otter species in Iran. Information about this species in Iran is absent. River ecosystems are one of the important habitats for otters. Jajrood River with 140 km length in the east of Tehran is one of these habitats that were selected for this study. To study otter distribution standard method was used. This method is a systematic sample survey for field signs of otters. 16 survey sites at about 5 km intervals were selected and Otter signs, habitat parameters such as vegetation cover, river width and fish of river were recorded for each 600m stretch by walking the entire it (both banks) of all river, wading in the river wherever possible. A total of 599 signs (spraints, tracks, holst,rolling places and passes) were identified over the whole study period, the most common being spraints. Otter spraints were found in 6 of the sites of river Surveyed and in the study area, three core areas could be identified.