Killer Whale (Orcinus orca)

Abstract

The killer whale, the ocean’s apex predator, has a cosmopolitan range through all the worlds oceans and most seas. It is the largest member of the family Delphinidae and has very distinctive black-and-white coloration. Only a single species, Orcinus orca, is currently recognized but it is probable that some of the genetically distinct forms found in different regions represent distinct species. Although a generalist as a species, different populations of killer whales usually have specialized foraging behavior and diets. These ecotypes often employ innovative cooperative hunting tactics to catch prey. Killer whales generally live in stable matrilineally structured groups from which dispersal of individuals may be rare on nonexistent. Killer whales produce highly structured, stereotyped calls that vary among populations and, often, among different maternal lineages. Once widely considered to be dangerous to humans or nuisances that interfered with fisheries, killer whales were widely persecuted. Today they are generally admired and protected, and are a focus of whale watching tourism in many regions. Availability of prey, acoustic disturbance, and contaminants are considered the primary anthropogenic threats to the species.