Killer Whales
The Killer Whales (Orcinus Orca), also called Orcas, are some of the most proficient hunters evolution has ever created. Part of the dolphin family, Delphinidae, Killer Whales are a combination of a whale, a dolphin, and a panda. They have black and white skin, are bigger than dolphins but smaller than most whales, and own a set of deadly, sharp teeth. Those teeth are well used, as the Killer Whales diet is very expansive, eating an expanse of different large prey. This prey can include seals and sea lions, various fish, walruses, narwhals, octopus, seabirds, and even other dolphins and whales! They sit at the top of the ecosystem, being an apex predator in most marine ecosystems it resides in, and impact the populations of most marine animals they share proximity to. Killer Whales can attribute their success as hunters to their abnormally large brain. This intelligence has allowed them to create strategies and plans in order to hunt their prey, and here's some of the most interesting methods these magnificent animals employ.
Wave Wash
Seals love to stay out of reach from Killer Whales, and will perch themselves on ice floats where Killer Whales cannot get to. But Killer Whales don't just give up, they group up in a formation, like fighter jets, and charge the ice float, creating a wave that knocks the seal off of it.
Above Image: https://roaring.earth/killer-whales-hunt-seals/
Karate Chop
Even sharks aren't safe from the might of Killer Whales, which has created a strategy to take them down. Using their tails, Killer Whales will bring the shark to the surface, slam their tails into the shark's head like a karate move, hence the name, and then flip them onto their backs. This accumulation of moves sends the shark into a stupor called “tonic immobility”, letting the Killer Whales safely feed on them.
Blowhole Block
While it seems like cannibalism for Killer Whales to eat other whales, they're actually more related to dolphins than whales. In order to attack such large creatures, they have formulated a strategy that employs the whole group. After attacking the weakest member of a whale group to tire it out, they will launch water onto the whale's back in order to prevent it from breathing. After hours of this pattern, the whale will drown through exhaustion and inability to reach the surface, and leave a humongous meal for the Killer Whales.
Geography & Population
The Killer Whales usually prefer colder waters, sticking to places like the arctic ocean, but they have been known to travel a lot. They move to new areas when the food becomes scarce, and don't seem to have many restrictions on where they go. They are considered to be a cosmopolitan species, being found in every ocean on earth. This is partly the reason why killer whales hunt so many different large animals, they have such a large range they live in that they encounter many more animals they can use their large brains to hunt.
The population of Killer Whales are much more concerning than their geographic range. Killer Whales travel together in pods, groups of individuals similar to a family, and will travel upwards of 160 km a day together, that's almost 100 miles a day! These pods help form the three different types of Killer Whale populations: Resident, Transient, and Offshore Killer Whales. Each of these types has small differences in their geographic range, diet, habitat, and even appearance, but they are known to share parts of their habitats. The sad and worrying part comes from the fact that these populations have steadily been getting smaller, and they haven't been able to repopulate fast enough. One population, the Southern Resident Killer Whales, dropped from a historic 140 individuals in 1960 to only 80 individuals in 2001. These decreases in population are signaling a real problem. Since the Killer Whales are unable to restore the lost individuals, their populations will only get smaller with time. A smaller population means less genetic variability, reducing the variation of these animals which helps them survive and evolve.