30+ Interesting Facts About Killer Whales

1. The killer whale, also known as the orca, is a toothed whale and a member of the oceanic dolphin family.  
2. The killer whale is the largest member of the oceanic dolphin family, with males and females reaching up to 8 m (26 ft.) and 7 m (23 ft.) in length, respectively. The largest recorded orca is a male with 9.8 m (32 ft.) length and more than 10 tones (22,050 lb.) weight. These mammals also have the tallest dorsal fins among crustaceans. The killer whale is also the fastest marine mammal that can reach the speed of 34.5 mph (55.5 km/h). (Source)
3. Killer whales are the most widely distributed mammals after humans and brown rats. They are present in all oceans around the world. On occasions, killer whales may also enter freshwater rivers. (Source)
4. Killer whales are social animals. They form groups of up to 15 individuals. The groups may temporarily expand to hundreds of whales and are dominated by female orcas.
5. Killer whales have sophisticated echolocation, like other crustaceans. They use whistles and pulsed calls for communication and social interaction. Clicks help in navigation and for identifying prey and other objects.
6. Killer whales are not always black. About ten completely white killer whales have been observed so far. (Source)
7. There are ten types of killer whales on earth. Five are present in the Northern Hemisphere, while the remaining 5 inhibit the Southern Hemisphere. These include Bigg’s orcas, resident orcas, offshore orcas, North Atlantic type 1, North Atlantic type 2, Type A orcas, Type B (large) orcas, Type B (small) orcas, Type C orcas, and Type D orcas. (Source)

   

   Killer whales consume 140 animal species

   
   
8. Killer whales are the largest predators of warm-blooded animals. Orcas eat 140 species of animals, including sharks, bony fish, rays, marine mammals, terrestrial mammals, sea birds, sea turtles, and others.
9. Few species of killer whales attack baleen whales (blue whales, humpback whales, etc.). During these encounters, orcas usually hunt the calves of these large whales. (Source)
10. There is no known incident of orcas killing a human in the wild. Instead, they have been seen playing with humans in their natural environment. (Source)
11. Since 1961, at least 166 orcas have been taken from the wild to captivity. Out of these, 129 have died till now. Currently, there are 60 killer whales in captivity: 29 were taken from the wild, while 33 were born in captivity. (Source)
12. A captive male killer whale killed three people (two trainers and a trespasser) in 1991, 1999, and 2010. This whale died in 2017 at the age of 36 years after spending 34 years in captivity. (Source)
13. The estimated worldwide population of killer whales is around 50,000. Their population in some areas declined in recent decades. 
14. The lifespan for female orcas in the wild is between 50 to 90 years. Male killer whales can live for 30 to 60 years in their natural habitat. 
15. The oldest known killer whale lived for more than 100 years. This female whale was part of research on menopause in mammals (only experienced by humans, short-finned pilot whales, and killer whales). (Source)
16. The brain of a killer whale can weigh up to 15 pounds. It is the 2^nd heaviest brain among marine mammals after sperm whales. (Source)
17. Killer whales are intelligent and use different techniques to hunt various animals. Their hunting techniques include karate chop (sharks), wave wash (seals), carousel (fish), storming the beach (sea lions and elephant seals), pod pin (narwhal), and blowhole block (larger whales). (Source)
18. Killer whales are the only known mammals that attack and hunt blue whales. They attack both calves and adult blue whales. At least one incident of killer whales hunting a pygmy blue whale has been observed. (Source)
19. Like other whales and dolphins, killer whales sleep by keeping their one eye and half-brain open. In this slow-wave sleep, the orcas close the eye on the opposite side of the sleeping brain. These animals switch the side of the sleeping brain after two hours to provide equal rest to both sides. (Source)
20. A female orca gives birth to a calf every 3 to 5 years. The average gestation period is 17 months and the nursing period is between 1 to 2 years.
21. Infanticide behavior is present in killer whales. The possible reason behind this behavior is sexual selection. (Source)

    

    Noise pollution from ships is harmful for orcas

    
    
22. Noise pollution from ships, food limitations, and ocean pollution are important factors decreasing the population of killer whales. (Source)
23. PCBs (polychlorinated biphenyls) are the biggest threat to the orcas in seas and oceans. These chemical compounds pollute fish and other marine animals eaten by killer whales. These banned substances were once in use to manufacture plastics, paints, electrical equipment, etc. (Source)
24. Responding to a request from Iceland, the US Navy killed hundreds of killer whales in 1954 and 1956 in Icelandic waters. (Source)
25. Killer whales are apex predators without any natural predators. They can hunt in the oceans freely without any fear.
26. Killer whales are more closely related to cows than other mammals on land, like wolves, elephants, and dogs. (Source)
27. Killer whales have excellent senses of hearing, vision, and touch. However, the sense of smell is absent in these mammals.
28. Killer whales have between 48 to 52 teeth on the top and bottom jaws, which assist in capturing and tearing prey. These whales can not regenerate their lost teeth.
29. According to a fossil discovery, orcas and false killer whales started eating large prey less than a million years ago. Before that, their diet was limited to small fish. (Source)
30. Older male orcas have very tall and straight dorsal fins. Females and younger males have small and sickle-shaped dorsal fins. 
31. Orcas are also known as “wolves of the sea” because of their social structure and unique hunting behavior.  
32. A unique hunting method of killer whales is by striking the beach at sea lion colonies. In the southern hemisphere, orcas usually employ this technique during March and April. (Source)
33. In contrast to most other animals, adult male and female orcas live alongside their mothers. The early death of the mother orca decreases the survival chances of males and adult females. (Source)