The killer whale/orca (Orcinus orca) is well known and can be identified relatively easily by its distinctive black and white markings and very tall, prominent dorsal fin. They can grow up to 9 m in length, with male dorsal fins reaching higher than a metre. Orca flippers are large and paddle-shaped and overall the body is robust. They are acrobatic and are commonly seen breaching and flipper-slapping.
Females and males differ in that males are longer and bulkier than females. Females have smaller, more curved dorsal fins and smaller flippers.
WHERE TO FIND ORCA
Orca are the most widely distributed mammal on earth with the exception of humans. They prefer deeper water but can be found in shallow bays and estuaries, and in inland seas. Orca can be found all throughout New Zealand's coastline — if we're lucky we see them out in the Bay of Islands frolicking in their pods.
DIET AND FORAGING
These dolphins have an extremely diverse diet and are the only known cetaceans that regularly prey upon other marine mammals. Attacks or kills have been documented on more than 35 species, including blue whales. Fish species are also important in their diet — salmon, tuna, herring, cod, sharks and rays. Squid, octopus, seabirds and sea turtles are also eaten. An average-sized killer whale may eat about 227 kilograms of food a day.
Orca hunt cooperatively and are even known to intentionally strand themselves on beaches temporarily in order to catch seals. Due to the orca's sophisticated hunting techniques and intelligence, Maori chiefs were sometimes likened to kākahi.
BREEDING
Females give birth to their first calf between 11 and 16 years of age and tend to do so every five years for their 25-year reproductive lifespan. The gestation period is 15–18 months and calves are nursed for at least one year. Females are known to live up to 80 or 90 years. Males reach physical maturity at about 21 years and live for a maximum of 50–60 years.