Killer Whale (Orcinus orca)

The Basics

Belong to the oceanic dolphin familyFound in all oceans Apex predatorsMatriarchal societiesImitate others, and teach skills to offspring

Are all Orcas the same?

Three to five types of killer whales, possibly different species

Resident: eat mostly fish and squid; complex and cohesive family groups; visit the same areas consistently

Transient: eat exclusively marine mammals; live in groups of 2-6 individuals; less persistent family bonds

Offshore: eat mostly schooling fish, may also eat mammals and sharks; live in groups of 20-75 individuals

Genetic data indicate the types have not interbred in the wild for up to 10,000 years.

Mitochondrial DNA sequences support that there are many newly diverged species within the orca category.

First split was about 700,000 years ago

Specs

Largest living members of the dolphin familyMales range 20-26 ft. long and weigh >6 tonsFemales range 16-23 ft. and weigh 3-4 tons Newborn calves are about 400 lbs. Able to reach speeds in excess of 56 km/hLive an average of 40 years in wild; average

of 25 years in captivityTotal population is >50,000

Fish are Food, Not Friends

Hunt in packsDifferent populations specialize eating different kind of prey.Eats 500 lbs. of food per dayCarousel feeding: use bursts of bubbles or flash white

underbelly to herd fish into a ball, which they then slap with their tails to stun or kill fish

Sharks: herd them to the surface and strike them with their tail flukes

Know how to induce tonic immobility in sharks and rays by holding them upside down

Whales: separate whale calves from mothersSometimes harass or kill other animals for no known reason

Sonar

Fun Fact: Dolphin’s sonar is not reflected by fishing nets. This is why they get stuck in nets so often.

Fatty melon and bottom jaw absorb reflected waves

Do not like U.S. Navy sonar

Orca Care

Orcas must be watered at least once per week.As of August 13, 2013, there are 45 orcas in

captivity worldwide, 32 of which are captive-born.

The Alliance of Marine Mammal Parks and Aquariums (AMMPA) goes further, and recommends 1,918 m3 for two killer whales.

 US regulations require 615 m3 for two killer whales. That is 48 feet long and 12 feet deep.

Dorsal fin collapseMake sure to vaccinate!

Thoughts?

Who has seen Free Willy?Why should or should not orcas be kept in

captivity?Do you think orcas have cognitive abilities

comparable to those of humans?Should intelligent animals be given human-

like rights under the law?Should we build orcas reverse SCUBA suits

so they can study our societies?