Orca/ Killer Whale

Orca/ Killer Whale
(Orcinus orca)
Life span
Orcas have an average life span of 25-35 years.
Size
Male orcas can grow between 7-8m and weigh over 5,000 kg. Females grow between 5-7m and weigh over 3,000 kg. The largest ever recorded male weighed over 10,000 kg and the largest recorded female weighed 7,000 kg.
Physical Appearance
Orcas are distinctively coloured. The dorsal surface is mostly black except for a grey 'saddle' behind the dorsal fin. The underside of the body and underside of flukes are white and there is white 'eyespot' behind each eye. They have a huge dorsal fin
Distribution
Orcas inhabit all the oceans of the world. Their distribution is limited by pack ice and they prefer cooler waters.
Diet
Orcas are top predators in the ocean. Their food preferences vary according to their locality. Prey includes marine mammals (other whales, seals, sea-lions, walruses), fish, squid and occasionally sea birds, sea-otters and penguins.
Social organization and behaviour
Orcas are highly social and live in groups called pods. Resident pods can consist of between 5-50 individuals and transient pod size varies from 1-7 individuals. Pods consist of males, females and calves and have a female dominated hierarchy.
Conservation/status
Status: Insufficiently known (IUCN 1996). Global threats include hunting, human disturbance, habitat loss, prey depletion, pollution, entanglement in nets and collisions with vessels. Orcas used to be killed by people to obtain meat and oil, but commercial hunting ceased during the 1980s.
Notes
Their dive lasts 1-4 minutes. The sounds they make help to echolocate, using screams, distinct tonal whistles and pulsed calls. Each group (usually 2-40 animals) has a repertoire of discrete calls that is unique to the group.