The size of a Killer Whale compared
to an average human
A Killer Whale Breaching
Resident Killer Whales (Orcas)
To listen to Killer Whale calls, click above
Latin/Scientific Name
Orcinus orca
Conservation Status
Conservation Dependent
Location
Worldwide
Colour
Black & White
Length
Up to 9 m (30 ft)
Weight
Up to 10 tonnes
(10 tons)
Life Expectancy
Average 35 Yrs (Male)
Average 50 Yrs (Female)
Main Characteristics
Killer Whales are the largest species of the oceanic dolphin family and they are known to be one of the fastest animals in the ocean, reaching speeds in excess of 56 km/hr (35 mph). They can grow to up to 9 m (30 ft) in length and they can weigh up to 10 tonnes (10 tones).
Killer Whales are distinctively marked with black colouration on their back and a grey saddle patch behind their dorsal fin. They are coloured white on the underside of their bodies and flukes, and they have a white patch behind each eye.
Their pectoral fins are large and rounded and they act as paddles when they swim. Their dorsal fin is extremely large and in males it can measure up to 1.8 m (6 ft). Males have larger pectoral and dorsal fins than females and their dorsal fin is more elongated and triangular, whereas dorsal fins of females are shorter and more curved.
Killer Whales are very vocal and they have highly distinctive cries, screams, clicks and whistles that they use for communication and echolocation. Vocalisations vary with activity and they are much quieter when they are resting. Each group have their own discrete calls that are unique to their own particular group.
On a daily basis the activities of Killer Whales can be divided into foraging, socialising, travelling and resting. They are very social animals and are enthusiastic with their displays of breaching, tail slapping and spy hopping. Breaching is where they lift their entire body out of the water and spy hopping is where they raise their heads up out of the water.
There are three different types of Killer Whale that are distinct enough to be considered different races or perhaps subspecies:
Resident - These are the most commonly sighted Killer Whales and they live in cohesive, complex family groups known as pods. They visit the same areas consistently and female residents have a rounded dorsal fin tip that ends in a sharp corner.
Transients - These Killer Whales travel in smaller groups that consist of 2 - 7 individuals. Females have a dorsal fin that is more triangular and pointed than that of resident Killer Whales. They may not stay together as family groups and they travel on extremely unpredictable routes; they may be seen once in a particular area and never return there again.
Offshore - These Killer Whales stay out in the open oceans and they have been sighted in groups of up to 60 individuals. Females have a dorsal fin tip that is continuously rounded and offshore Killer Whales tend to be smaller than both residents and transients.
Habitat
Killer Whales are found worldwide and residents live in pods of up to 50 individuals. The pods are matriarchal and both male and female calves stay with their mother for their entire lives. When they breed their create multigenerational groups and it is not uncommon for a pod to consist of 4 or 5 generations. Their range varys between 320 Kms (200 miles) and 1300 kms (800 miles).
Transient pods usually consist of up to 7 individuals as some male and female off spring eventually leave the maternal group. Their home range is much larger than that of resident Killer Whales.
Diet
Killer Whales are apex predators and they prey upon a variety of animals. On average they will consume up to 227 Kgs (500 lbs) of food per day. Specific populations of Killer Whales are known to specialise upon particular prey species.
Residents mainly feed upon fish and squid. Over 30 different species of fish fall prey to Killer Whales and these include salmon, tuna, herring, basking sharks, oceanic whitetip sharks and smooth hammerhead sharks. Transients almost exclusively feed upon marine mammals such as sea lions, seals, minke whales and grey whales. Offshore Killer Whales primarily feed upon sea turtles, fish and sharks.
Sea birds, penguins, walruses and sea otters are also occasionally preyed upon by Killer Whales as are terrestrial mammals such as deer and moose, that have been swimming between islands off the north west coast of North America.
Killer Whales often use complex hunting strategies to find, subdue and kill their prey. They hunt in pods and they chase down prey or herd fish together then attack from different angles. They also head butt prey or slap them with their tail flukes to stun them, intentionally beach themselves to catch sea lions in the shallows or tip over ice flows to unbalance penguins and seals.
Breeding
After a gestation period of 15 - 18 months, Killer Whales will give birth to one calf. They can give birth at any time of the year, but it generally occurs during the winter months. At birth the calves weigh approximately 180 Kgs (400 lbs) and they are approximately 2.4 m (8 ft) in length. Calves will feed from their mother for up to 2 years, but they will begin to eat solid food when they reach 12 months old.
All resident Killer Whale pod members will take care of young whales, but calf mortality is high with approximately 50% of them not reaching 6 months old.
Females become sexually mature at 15 years of age and they will reproduce once every 5 years until they are 40. Males become sexually mature at around 15, but do not usually reproduce until they reach 21. Killer Whales within a pod do not interbreed; mating occurs with individuals from different pods.
Predators
Killer Whales have no natural predators but they are preyed upon by humans.
