Facts About The (Orca) Killer Whale

Killer Whale (Orca) Orcinus orca

You may not know

Killer Whales, also known as Orca, are not whales at all, they are actually the largest member of the dolphin family.  

Size

These mammals are massive, with a body weight of 6 tons, and spanning nearly the length of a school bus, some even reaching lengths of 32 ft.  

Food Items

They feast upon marine mammals such as, seals, sea lions, other dolphin, and even whales. They also hunt fish, squid, and seabirds. 

Habitat

Killer whales frequent, colder coastal waters, but can be found from the polar regions to the Equator.

Hunting

Killer whales travel in lethal pods of up to 40 members, there are both resident and transient pods, these groups hunt different prey items, the resident pods prefer to hunt fish, while the transient prey on marine mammals. Both types using different hunting strategies and techniques, but all orca pods are cooperative hunters, that many compare to the wolf.

Hunting Techniques

Using the “Wave Technique” The pod will divide ice flows, push a patch of ice out to sea, and swim on the surface of the water, towards the freely floating patch, with which a seal is laying, creating a wave, and knocking them off the ice into the water, where they finish the seal. This behavior has only been documented in the Antarctic Peninsula, and no where else in the world. 

Another technique they use is called “Breaching” where the animal will actually breach from the sea, with nearly half of it’s body on the earth, and grab an unsuspecting seal.

Mating

Females come into estrus or “heat” several times during the year. Breeding may occur in any season, but is most common in summer. In the North Atlantic, mating seems to peak in October and November; in the western North Pacific, mating seems to peak between May and July.

Calves

The calf is about 8 ft. (2.4m) long and weighs about 300 to 400 lb, at birth

They can have yellow rather than white markings, but they turn white by adulthood.

The calf suckles from nipples concealed in abdominal mammary slits. Killer whale calves begin nursing several hours after birth. Calves nurse below water, close to the surface. The mother glides in a horizontal position with her tail arched, and the calf swims on its side with its mouth on the right or left mammary gland. Calves nurse for about 5 to 10 seconds at a time, several times an hour, 24 hours a day. The mother’s milk is very rich so that the baby rapidly develops a thick, insulating layer of blubber. The fat content of the mother’s milk increases as the calf develops. It ranges from about 28% to 48%. A calf may nurse for 12 months. A mother killer whale stays close to her calf and attentively directs its movements. The baby swims close to its mother and can be carried in the mother’s “slip stream,” a type of hydrodynamic wake, which develops as the mother swims. This helps the baby swim with less energy and enables the mother and calf to keep up with the pod. While most maternal behaviour is probably instinctive, first-time mothers are inexperienced at nursing their calves. The experience level of some first-time pregnant females is increased through training procedures that teach them to respond to nursing behaviour. To nurse, a calf swims on its side and suckles from nipples concealed in abdominal mammary slits.