The use of spraints to survey populations of otters Lutra lutra

Because the survey of distribution of faeces (spraints) of otters is so frequently used in the assessment of otter populations and otter habitat use, we have studied the spatial relation between sprainting and various criteria of otter activity and presence. In a marine habitat on Shetland spraints were found to be associated with otter holts and habitat features, such as freshwater pools. There was no correlation between sprainting and the frequency of use of an area by otters. This casts doubt on the use of spraint surveys as a method to assess habitat utilisation by otters. It is argued that, with reservation, spraint surveys may be used for comparing otter populations between large stretches of river, or coast, with similar vegetation and physiography.