A historical approach to describing the complex behaviour of a large species of predatory shark — case study 2: the white shark, Carcharodon carcharias

Abstract

A historical example, case study 2, is one of two cases illustrating the complexity of interactions between sharks in their natural environment. Evidence is presented that the white shark is a selective feeder, consuming seals and sea lions with high fat content yet rejecting a pelican, human, and sea otters with low fat content. After biting seals, these sharks carry them in their jaws for a prolonged time underwater to kill them through blood-loss, i.e., exsanguination. Multiple sharks compete to feed on the remaining seal carcass when it floats to the surface. The sharks perform the Tail Slap, consisting of lifting the caudal fin and splashing water toward the accompanying shark. A combatant is permitted to feed further on a seal only if the vigor and frequency of its tail slaps are greater than those of its opponent. Thus, this is an agonistic display, functioning to ward off potential competitors.