Displacement Activities in Fiddler Crabs

Abstract

ACCORDING to Tinbergen¹, a “displacement activity is an activity belonging to the executive motor pattern of an instinct other than the instinct (s) activated”, and, according to Bastock, Morris and Moynihan², such activities would seem to take place in two quite different situations: “(1) Displacement activities may be performed by an animal in which two or more incompatible drives are strongly activated. Each drive prevents the expression of the other(s). (2) Displacement activities may also be performed by an animal in which one drive is, at the same time, both activated and thwarted.”