Killer Whales: The Apex Predators of the Sea
Killer whales, also known as orcas, are apex predators and are considered to be the "wolves of the sea." They hunt in pods, often working together to encircle and herd prey before attacking.
Hunting Techniques and Communication
When hunting, killer whales may attack from multiple angles, including head-butting, slapping, jaw-snapping, and biting. They also use a range of postures and gestures to communicate with their pod and other members.
Interactions with Humans
Despite their name, there have been no reported attacks from orcas against humans in the wild. However, there have been attacks in captivity - one of which killed a trainer at SeaWorld.
Life Cycle and Behavior
Orcas can live for 40 to 50 years and are highly social mammals that have a strong bond with their mothers. These bonds are key to their survival and can increase a mother's likelihood of raising her young.
Diverse Diet and Feeding Habits
These whales are omnivorous, eating a wide variety of marine animals, from fish to seals to seabirds and squid. They can also take down whales that are larger than themselves, including minke whales and great white sharks.
The Mechanics of Breathing
They have powerful blowholes that produce a spout of water that rises when they exhale. The whale breathes through a muscular flap that covers its blowhole. The flap is relaxed in a closed position when it is submerged and opens and closes at the surface of the water. The spout of water that rises is produced by the exhalation of carbon dioxide and other gases from their lungs. The spout is formed by the combination of the pressure of the exhaled air and the movement of water through their pores. As the whale's air fills its lungs, it expands, which forces the water from the mouth to the blowhole.
Anatomy and Adaptations
In addition to their blowhole, killer whales have vents and a large cavity under their skin. These cavities contain organs that regulate the whale's body temperature. When a killer whale dives, it reduces circulation at the skin, shunting blood to its insulated body core. The excess heat is then dissipated through its flippers, flukes, and dorsal fins. Their skeletons are dense, so they are able to survive long periods of time in cold water. The whale's ribs are covered with cartilage that helps protect the bones from injury. They also have a thick coat of blubber that helps them retain body heat.
Social Structure and Group Dynamics
Killer whales are incredibly social animals and live in social groups called pods. Individual whales typically stay within their pods for life; they often stay in the same pod from birth until death. A pod of orcas usually consists of several to 20 whales and is led by a matriarch who passes on her skills and behaviors to each generation of whales in the family group. During mating season, whales form larger groups of a few to 20 whales for short-term social interactions and mating.
Dangers and Vulnerabilities
They are very apex predators and can be aggressive toward other animals when they find prey that is too large or difficult to take down on their own. They also have an exceptionally high tolerance for toxins and diseases, as well as for stress, which makes them particularly vulnerable to the effects of human activity in their ecosystems.
