Killer Whales 

 

Latin Name: Orcinus orca
Other names
: Orca, Blackfish

 

Description

Killer Whales are the largest members of the Dolphin family. They are classified as large toothed Cetaceans.  They have a cone-shaped head and streamlined fusiform body. They are incredibly distinct large mammals with black and white markings and a grey saddle patch located behind their dorsal fin. They use their tail (fluke) for propulsion through the water, pectoral fins for direction and steering, and their dorsal fin aids them in stability.

·       Males are generally physically larger than females. Mature males can reach up to 7.5–9.5m and weigh up to 5,600kg. The dorsal fin can reach up to 2 m in height, and they fully develop in their early 20's. Mature females reach up to 7.8m and weigh about 3,600kg. Once mature at the age of 13-14, females will  give birth and continue to give birth once every 4-5 years until they reach their early-mid 40's. Females live a lot longer than males, with females in the wild having a life expectancy of 80 to over 100 years. Males make it to about 40-60 years old.


Southern Resident Orca, Omega, Vancouver Island, BC
Orca porpoising, Vancouver Island, BC


How often and when we see them?

Killer Whales or Orca are the main animal we aim to sight on every tour. The chances of sighting Killer Whales does vary depending on the time of year. During the summer period you have the greatest chance of sighting them, which is because of the large and extensive spotting system in place during the summer time. During the winter months, the chances decrease from 100% to about 60%, as there are always whales in the local area. However, instead of being 30-50 boats and spotters looking for them, there are two or three boats which does make locating them a little bit more challenging. The two types of Orca we see around Southern Vancouver are the Southern Residents and the Transients.

 Surface Displays

Killer whales have various displays on the surface that are commonly observed. Make no mistake, in the North East Pacific, killer whales are the top predator. They are such efficient hunters that they only spend about 10% of their time hunting, and the rest of their time is set aside for playing, socializing, resting and teaching one another. The basic displays/behaviours you see on the surface of the water include:

  • Surfacing - The most common sight. This is seen when they come to the surface to breathe, and is usually followed by a small cloud of mist (exhalation) coming from their single blow hole.
  • Spy Hopping - This is when they are vertical in the water and their head comes out of the water. They are looking around, most probably at you!
  • Breaching - They jump out of the water and their body is exposed momentarily.
  • Porpoising -  This can be seen when a killer whale or pod is moving at high speeds. When they surface to breathe, the majority of their body comes out of the water.

 

 

 

 Interesting facts

  • Distribution - this marine mammal has been sighted in every ocean in the world, from tropical to polar!
  • Genetic Diversity - Killer Whales have very little genetic variation between global and regional populations, which strongly suggest a strict matrilineal expansion of local populations, and a possible historical bottleneck scenario (Hoelzel et al. 2002). This means that once upon a time the population of killer whales decreased dramatically, which reduced its available genetic variability. The population slowly recovered to what it is today.
  • Sleeping & Breathing - Killer Whales are voluntary breathers. This means that they must make the actual effort to breathe every single time, so going to sleep could be an issue. Killer whales do have the amazing ability to shut down half their brain at a time, so when "sleeping" occurs, the Orca has actually shut down one side of their brain while the other half controls their breath.

In the waters that surround the southern part of Vancouver Island, there are two different types of killer whales that are frequently sighted. These two forms do not mix, and even seem to avoid each other. They differ in social structure, behaviour, acoustic, genetic and seasonal distribution.

 

·    Southern Residents

·   Transients 


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