The NATO Advanced Research Workshop on "Behavioural Adaptation to Intertidal Life" held in Castiglioncello, Italy (May, 1987) was attended by 50 participants, most of whom presented requested lectures. It was perhaps the first time that specialists of various animal groups, from cnidarians to birds, were able to meet and discuss the importance of behavioural adaptation to this peculiar, sometimes very harsh environment. But the taxonomic barrier is not the only one which the meeting attemped to over­ come. Lately, the research on intertidal biology has spread from pure taxonomy and static analysis of community structure to such dynamic aspects as intra- and interspecific relationships, and physiological mechanisms aimed at avoiding