Orcas, often called killer whales, are apex predators of the ocean. As the largest member of the dolphin family, their size frequently captures public interest. Understanding the dimensions of these marine mammals provides insight into their biology and their place in marine ecosystems.
The Largest Known Orca
The largest male orca ever reliably recorded measured 9.8 meters (32 feet) in length and weighed over 10,000 kilograms (22,000 pounds). This individual was a male found stranded on Piken Island, Alaska, in 1959. These records often come from historical data or measurements of deceased, stranded individuals, allowing for more precise evaluation than observations in the wild.
Another male was “Old Tom,” an orca observed in the late 1800s off the coast of Australia. He was estimated to be over 9 meters (30 feet) long and weighed more than six tons. For females, the largest recorded individual measured 8.5 meters (28 feet) and weighed 7,500 kilograms (16,500 pounds). These exceptional cases highlight the upper limits of orca size, significantly surpassing the typical dimensions of most individuals.
How Orca Size is Determined
Scientists employ various methods to determine orca size. For deceased animals, direct measurements of total body length, from the tip of the snout to the notch in the fluke, can be taken. Weighing these individuals also provides accurate mass data, difficult to obtain from live animals. Skeletal analysis from post-mortem examinations also provides physical dimensions.
Measuring live orcas in their natural habitat presents a greater challenge, requiring non-invasive techniques. Photogrammetry, utilizing unmanned aerial vehicles (UAVs) or helicopters, is a tool. By taking straight-down photographs from a known altitude and using the camera’s focal length, researchers can precisely calculate the length and even assess the body condition of individual whales without disturbance. This method helps scientists monitor growth and health within wild populations over time.
Typical Orca Dimensions
Average orca size provides insight into the species’ typical dimensions. Adult male orcas are larger than females. Males average between 5.8 to 6.7 meters (19 to 22 feet) in length and weigh from 3,628 to 5,442 kilograms (8,000 to 12,000 pounds). Their dorsal fins can be tall and straight, reaching up to 1.8 meters (6 feet) in height.
Female orcas are smaller, ranging from 4.9 to 5.8 meters (16 to 19 feet) long and weighing between 1,361 to 3,628 kilograms (3,000 to 8,000 pounds). Their dorsal fins are more curved and shorter, averaging 0.9 to 1.2 meters (3 to 4 feet). Orca size can also vary depending on their ecotype, with some populations, such as the Antarctic Type A orcas, exhibiting larger average sizes, while others, like the Antarctic Type C, tend to be smaller.