6. Operation Orca
Description
Meet the ultimate marine predator on the planet: the killer whale. The name originally being “whale killer” itself was given to them from ancient sailors who witnessed the killing power of these beasts. The term was eventually flipped. The Latin origin, Orcinus, means ‘of the kingdom of the dead’. This meaning is derived from the Roman god Orcus who was from the netherworld and punished those who did evil. The English definition for ‘Orca’ means “barrel-shaped”, so you can follow whichever definition you like best (aka the Latin one).
Credit: BestAnimations
Meeting an Orca:
If you were to meet the average orca, this is what you would find:
-That they are heavier than a piano (roughly 12000 lbs)
-They’re slower than a car (though still pretty fast at average 30 mph)
-They are just a little bit shorter than a school bus (on average orcas are 23-32 feet)
-If you get real close to an orca, you will see about 45 teeth, averaging at 7.6cm smiling back at you.
-They are famous for their black and white coloring used for counter shading and their dorsal fin that cuts through water as it towers up 102 metres tall.
-If you meet one orca, it’s likely there’s more where nearby as they are very social creatures that travel and hunt in pods. This occurrence has caused them to be nicknamed ‘wolves of the sea’.
*The Ultimate Fact*: Killer Whales aren’t actually whales. They are actually the biggest member of the dolphin family.
Gif Credit: Pinterest
Diet:
Orcas have a vast population that make them generalist eaters; they can eat fish, seals, sea lions, dolphins, porpoises, sharks, rays, large whales, cephalopods, seabirds and even great white sharks. They’re carnivores so they can swallow up small seals or rip apart a ray. However, even though they have the ability to eat pretty much any other animal, they are also quite picky. So different orcas groups prefer different prey. It’s theorized that they’ve learned from their pods families what to eat which helps prevent them from exhausting food resources.
They also have fin-tastic teamwork for hunting prey; a skill that leads scientists to believe that they have strong social skills and high intelligence. Just check it out for yourself:
Video Credit: BBC Earth
Bonus fact: Scientists have noted that orcas also eat moose swimming in the ocean and polar bears if they get that rare chance!
Communication:
One of the main ways it’s believed they are able to conduct such fancy teamwork is through their communication via whistles and body language.
Each pod has their own distinct ‘accent’ which is taught from generation to generation. It’s this range of vocalizations that tells messages of what to avoid, what to catch and where to find it. These dialects of sorts are of particular interest to scientists to help define differing pods and to better understand how knowledge is passed on from elder to youngling.
Gif Credit: Pinterest
For instance, studies have shown that the resident populations of orcas in the Pacific Ocean are noisier than transient killer whale, despite the fact that they share these waters.
Unlike us humans with our vocal cords, orca’s you compacted tissue in their nasal cavity to produce sound. The sounds they produce are categorized into 3 types: whistles, discrete calls and clicks. Whistles and the discrete calls are usually for communication for the pod and click are for echolocation in order to scan their environment. They hear with their small opening behind their eyes (thought not easily identifiable).
If you’d like to learn how to ‘speak Orca’ take a look at this list of lingo:
-Breaching: When they thrust out of the water to land in a big splash. It’s very loud and can be hear for great distances both above and under the water. This is particularly useful when orcas aren’t within visual range of each other.
-Charging: A very forceful form of communication in which an orca charges another animal to hit or narrowly hit them. Similarly to dogs, this can be a form of playful behavior or a very serious form of dominance.
-Lobtailing: this is the slapping of their tails or flippers to garner attention for fun or for giving an alert to others
-Spyhopping: When they lift their head ever so slightly above the water to get a view of their surroundings above water.
-Light nurturing touches: A moment of affection between a mother and calf or between two orcas interested in mating.
Species:
As I mentioned briefly above, there are differing groups of orcas that have their own cultural systems in place (aka. Forms of communication and preferences of prey). Along the Pacific Canadian waters, there are Transient Orcas and Resident Orcas. Here are some key differences between them:
Gif Credit: Pinterest
Resident Orcas: They feed exclusively on (mainly Chinook) salmon and call the Pacific Northwest home. There are two subgroups of resident orcas: Northern residents who are found around Vancouver Island to Southeast Alaska and Southern residents who are found around Puget Sound. As the salmon they hunt aren’t highly aware of the sounds orcas make, the orcas tend to be a lot noisier in this group.
Transient Orcas: They feed mainly on marine mammals. They travel between the north and south coasts by Southeast Alaska and British Columbia down towards California. They sometimes visit the waters of Puget Sound to hunt for harbor seals. They typically hunt and travel in small pods of 2-6 members. They are sneaky hunters as they do not breach or splash; they creep up with the ultimate stealth.
Sleeping:
Gif Credit: Gyfcat
An odd fact that few know is that orcas remain conscious when they sleep. This is due to their need to consciously take breaths of air- it doesn’t happen automatically like us humans. Because of this, they turn off only half of their brain at a time. This way they can regulate their breathing and stay alert for danger. This type of sleeping is called unihemispheric sleep, and it what lets the orcas alternate the sides of their brains to shut down for bedtime.
Questions for Your Jr. Biologists:
- Why do different pods of orcas have differing ways to communicate? Each pod is a tight knit family that has its own culture of sorts. This means that they learn from their elders what to eat and how to communicate and that information ranges from pod to pod.
- What do orcas eat? This varies greatly. Orcas are carnivores so they can eat pretty much any marine animal they like, however they are quite picky. For instance, resident killer whales prefer Chinook salmon whereas transient killer whales prefer seals and sea lions.
- Why do orcas sleep with half of their brain on?: They sleep by the surface so they can consciously regulate their breath and be aware of potential dangers in their environment. It's an odd way to sleep, but they are able to make it work with each side of the brain taking turns to sleep.
- Do you have any questions for Club Volunteers or our Coordinator, Jordan ? Ask away on our Discussion Board!
Task
-Get crafty with these top killer whale projects here
-Check out 3D images of orcas here
-Check out the B.C Cetacean Sightings Network
Learning Objectives
-Understand the differing ways orcas communicate
-Acknowledge the threats that impact orca populations
-Learn the differences between transient and resident orcas
-Observe the social groupings and strategies of orca pods
Continue to 7. Mission Migration »
