False killer whales (Pseudorca crassidens) are intriguing marine mammals that often spark curiosity due to their distinctive name. This name can lead to common misconceptions about their identity, particularly regarding their relationship to the well-known killer whale. This article delves into the true nature of false killer whales, exploring their classification, physical attributes, typical diet, and, most importantly, whether dolphins form a part of their prey.
Who are False Killer Whales
False killer whales (Pseudorca crassidens) are classified within the oceanic dolphin family, Delphinidae, despite their common name. They share a skull shape similar to that of killer whales (Orcinus orca), which is the origin of their name, yet they are not closely related.
These sleek marine predators possess dark gray to black bodies, sometimes with a faint lighter patch on their chest. Their heads are rounded without a discernible beak, and they feature 8 to 11 conical teeth on each side of their jaw. Adult males can reach lengths of up to 6.1 meters (20 feet), while females typically grow up to 5 meters (16 feet), with adults weighing between 917 to 1842 kilograms. False killer whales are found globally in tropical and temperate oceanic waters, inhabiting vast areas across the Atlantic, Pacific, and Indian Oceans, though they prefer deeper pelagic environments.
Their Natural Diet
False killer whales are apex predators within their marine ecosystems, primarily feeding on large fish and squid. Common fish species in their diet include swift pelagic fish such as tuna, mahi-mahi (also called dorado), wahoo, bonito, and even sailfish. They are known to discard certain parts of their prey, like the tail, gills, and stomach, before consumption.
Predation on Dolphins
While large fish and squid constitute the primary diet of false killer whales, observations confirm they prey on other marine mammals, including smaller dolphin species. Documented instances exist, revealing their opportunistic predatory tendencies. Specific examples include common, spotted, and bottlenose dolphins. Evidence comes from direct observations, analysis of stomach contents, and behavioral studies.
This predation, although not their main food source, highlights their flexibility as hunters and their capacity to adapt their diet based on factors like prey availability and specific environmental conditions. Beyond smaller dolphins, false killer whales have also been observed attacking larger cetaceans, such as sperm whales and humpback whale calves, though the exact motivations behind these larger attacks, whether for food or competition elimination, are sometimes debated.
Coordinated Hunting Behavior
False killer whales are highly social animals that typically hunt in cohesive groups, often referred to as pods. These groups can vary in size, ranging from a few individuals to hundreds, though they commonly consist of 10 to 60 members. Their cooperative hunting strategies are a key to their success in capturing fast-moving and large prey.
They employ echolocation, a biological sonar system, to detect and track prey in the open ocean. False killer whales often hunt in dispersed subgroups, converging once prey is located, and have been observed sharing their catches among pod members. Their social structure and coordinated efforts enable them to effectively pursue and capture a wide array of marine life, including both the large fish that form their staple diet and other marine mammals.