Hunting techniques are passed down through generations, so their diets depend on the region they inhabit and the pod's approach to hunting. These highly intelligent cetaceans have been documented creating large waves to wash seals off ice floes, and even intentionally beaching themselves to catch prey on the shore. Read more about what whales eat. Smart cookie preferences. Change cookie preferences Accept all cookies. Sometimes they beach themselves to catch seals on land, jumping from the water onto land.
They can use echolocation to identify their prey by creating sounds, or sound waves, that travel through the water. These waves echo off objects, including prey, which the orcas can use to locate them, according to SeaWorld.
There is no record of an orca ever killing a human in the wild. This is because humans are not part of their natural diet. Occasionally, an orca may mistake a human for something they do eat, such as a seal. In , an orca was caught on camera charging at a surfer during the Lofoten Masters surfing competition in Norway. The orca seemed to pull out of the attack just before making contact. The Norwegian Orca Survey said in a Facebook post that the orca likely realized the surfer was not a seal at the very last second.
In , a year-old boy was "bumped" by a killer whale near Ketchikan, Alaska, in what may have been an aborted attack — similar to the surfer in Norway — or simply curiosity on behalf of the orca, according to the Associated Press, via The Seattle Times.
The Associated Press reported that a surfer was bitten in California in the early s, which is the only relatively well-documented case of a wild orca actually biting a human. Orcas in captivity, however, have attacked and killed people. Although wild killer whales do not intentionally harm people, they have attacked boats. There were many reports beginning in the summer of of orcas ramming into and causing damage to sailing boats off the coast of Spain and Portugal, according to BBC News.
Three juvenile male orcas were involved in most of the attacks, and marine biologists investigating the incidents believe that the young males were playing with the boats by targeting the rudders and pushing the boats around. Orcas are very social creatures and live in family groups called pods, which have up to 50 members, according to the University of Michigan's Animal Diversity Web ADW.
These pods are made up of related mothers and their descendants, known as matrilines. A male orca will stay with its mother for life, while daughters may spend time away after having calves of their own, according to the wildlife charity Whale and Dolphin Conservation WDC. Pods often have their own distinctive calls, or dialects, to communicate, but they will associate with other pods and can come together to form even larger, temporary groups.
A female killer whale will give birth to one offspring at a time every three to 10 years. The gestation period usually lasts for around 17 months according to SeaWorld. Orcas work together to take care of the young, and other females in the pod will often help with the rearing.
Female killer whales have an average life span of 50 years, but some individuals are estimated to have lived up to years. Males live shorter lives, with an average life span of 29 years and a maximum life span of 60 years, according to the Center for Whale Research in Washington state. Killer whales are the most widely distributed mammals, other than humans and possibly brown rats, according to SeaWorld. The tags show when and how a whale is swimming or diving, and even whether a hunting attempt is successful.
Hydrophones on the tags provide another level of detail—right down to the crunch of a captured chinook salmon and the sound of a whale rubbing itself on the beach. After several hours, the suction cups lose their grip and the tag floats to the surface, emitting a radio signal that helps the researchers find it.
The signal can echo off the land, turning an archipelago into a pinball machine. The study is expected to continue for another two years; analysis of the information is a huge undertaking that should yield a treasure trove of information on killer whale behavior. Previous research using less sophisticated technology showed that southern resident killer whales—a distinct, endangered population—swim slower and dive less often at nighttime.
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