Wolves of the Sea

Orca, or Killer Whales, are sometimes called ‘wolves of the sea.’ Orcas have no natural predators and often hunt in packs like wolves.

Killer whales can be found in all oceans, most seas, and even in some rivers. They are also tolerant of most water temperatures.

Range

Orcas can be seen on the Oregon coast in several locations, particularly in mid-April when the gray whales are returning.

Generally, they are found along the Pacific west coast from California north into Alaska. Killer whales have also been seen at Depoe and Yaquina bays, and Newport.  

Orcas have been spotted on large rivers (as in 100 miles upstream on the Columbia most likely hunting seals).

Diet

Their diet will vary depending on food productivity. As the level of productivity goes down, their diet becomes more generalized.  Some specialize and focus on a particular (most likely abundant) prey species in a particular region.

They hunt fish, squid, octopi, mammals (otters, seals, swimming deer), seabirds, squid, octopus, cuttlefish, sharks, nautilus, and other whales. Killer whales eat around 100 lbs of food each day.

Maternal Groups

Some orca populations, or pods, have complex and stable social groups and may include 50 individuals.  Several generations will travel together, and with only short separation periods (for foraging and mating).

An Orca may live with its mother as part of a pod for their entire life. Orca form matrilineal (matriarch, or eldest female) family groups.

Matrilineal family structures are the most stable. No other species has such a complex social structure.

Pod members help teach young Killer whales how to hunt and parent through apprenticeship, among other skills. 

Social Structures

A pod can contain several family groups. Males nearly always mate with females from other pods.

Pods may co-mingle to create a clan. Clans typically share similar dialects or vocalizations and potentially older Maternal lineages.

Clans can also regularly commingle to create a ‘community.’  Communities, however, may not share the same vocal patterns.

Vocalization, or dialects, can be specific to a particular clan. A lack of shared dialect suggests that there may be more than one species of Killer whale.

Identification

You have probably seen pictures of a Killer whale. They are very identifiable due to their size (huge), color (black and white warning colors), teeth (big and sharp), and similar to dolphins. All white orcas have been found.

This apex hunter is often significantly larger than most great white sharks. The arrival of orcas in an area can cause white sharks to flee and forage elsewhere.

Killer whales are the largest members of the dolphin family. Males can grow up to 26 feet long and weigh over six tons. Females are generally a bit smaller growing up to 23 feet long and weighing about three to four tons.

These giant dolphins are born large weighting in about 400 pounds at birth and already nearly eight feet long. Even so, nearly half of all newborns die before their first birthday.  

Unlike other dolphin species, this animal has a well-developed protective dermal (skin) layer that includes a dense network of collagen fibers. Beneath the skin, orcas have a nearly four-inch layer of insulating blubber.

Hunting

Killer whales are amazing apex hunters. Orcas typically swal­low small prey whole and tear up larger prey. A few facts about orcas:

• They are so­cial hunters, similar to wolves, that work as a pack to hunt large prey. They use coordinated behaviors and communication which may be specific to a particular pod.
• Orcas have very sophisticated echolocation abilities (like other dolphins). They can identify the location and characteristics of prey or objects in the water.
• These dolphins also have good eyesight above and below the water. They also have excellent hearing and a good sense of touch.
• Typically, they spend most of their time in shallow waters but will occasionally dive several hundred feet to reach prey. As they dive, they are able to reduce their heartbeat per minute from 60 to 30 which helps them conserve energy.

Humans

Killer whales have been a part of many indigenous cultures and widely regarded with respect. This has not always been true.

For some time, orcas were hunted for entertainment (shows, zoos, etc.). This practice is being dramatically discontinued.

Several elements make these animals difficult to maintain in captivity (social structure, size, etc.). Generally wild orcas have not killed or harmed humans. This is not the case for stressed-out captive whales.

A lack of knowledge affects our ability to measure populations, identify different species, and track them. See Oregon Whale Watching!  

REFERENCES:
–Oregon Dept. of Fish and Wildlife, Orca (https://myodfw.com/wildlife-viewing/species/killer-whale)
–Animal Diversity (https://animaldiversity.org/accounts/Orcinus_orca/)
–Wikipedia, Killer Whales and several other terms like ‘Cephalopoda’ (https://en.wikipedia.org/wiki/)