Many species of mammals live in close association with rivers and streams, often feeding in them and frequently using them as a place of safety and as a means of escape from predators. Modifications of species for swimming and diving may involve such profound anatomical and physiological specialization that they are at a relative disadvantage to terrestrial species when on land. Indeed, the degree of aquatic specialization exhibited may be a corollary of the frequency with which an animal needs, on occasion, to return to a terrestrial life. The mammal exploiting a semi–aquatic lifestyle often suffers other limitations in addition to those consequent upon its habitat–specific adaptations. For example, in recent years many of our rivers have become highly polluted, draining as they do a highly modified landscape where bankside modification for agriculture/forestry, enhanced water flow, or recreation, has further reduced their suitability for the highly specialized animals that inhabit them.

In November 1995 a conference on the subject of the Behaviour and Ecology of Riparian Mammals was held at the Meeting Rooms of the Zoological Society in London. The idea behind the symposium was to bring together scientists from a range of disciplines but all researching the behaviour and ecology of a group of mammals united by their adherence to a semi–aquatic lifestyle. It was hoped that such a comparative approach would lead to a clearer understanding and would be of value to those charged with the task of undertaking their conservation and management.