Orcas

KILLER WHALE(Orcinus Orca)

a.k.a Blackfish

Just the name itself sends chills down the spines of many. Yet on the other hand, looking at their invitingly playful smiles makes you want to give them a hug. So the question now is, are they a friend or foe?

Decades ago, their reputation precedes their name, as vicious killers, causing them to be killed and hunted out of fear. However, in the recent years, there's a new found respect for these elegant killers. Indeed, they are the top predators in the ocean, but these dolphins have the intelligence to kill only for food and not for pleasure; up to now, there hasn't been any cases of wild Orcas killing humans even though humans are their natural predators.

Yes, you read it right. The Killer Whale or more commonly known as Orca, are in fact mammals that fall under the category of the dolphin (Delphinidae) family and not whales. In addition, they are the biggest, most vicious and fastest member of the family; having the ability to travel with a speed of up to 65 km/h.

*Killer whales are the most widespread mammal on the planet, besides humans*

Orcas are always traveling and moving around which is why there are still plenty about them that we do not know. But these are the basic facts about these elegant creature.

Average weight: Male (up to 10000kg) Female (2600kg to 3800kg)Average size: Male (up to 9m or more) Female (up to 7.7m or more)Average lifespan: Male (50-60 years) Female (up to 90 years)

Food: Fish, squid, marine mammals (seals, porpoises, walruses,large whales), manta ray, birds, penguins, turtles and even some sharks. Some types of Orcas differ in size, coloration, social groupings, habitat and even preferred prey.

*These elegant hunters are not fussy eaters and they eat up to an average of 227kg of food each day*

As of right now, the scientific community distinguishes Orcinus Orca into 3 seperate types.

1) Transient pods: - Move around a lot more and consume marine mammals - Dynamic in social structure - Pointier dorsal fins - More silent to avoid alerting prey - Have about 4-6 distinct calls - Move in smaller pods

2) Resident pods: - Live year round in one spot and eats mainly fish - Rounder with more curved dorsal fins - More vocal, silent only when they are sleeping - Have 7-17 dinstinct calls

3) Offshore pods: - Attack sharks - There's a massive lack of info about this type of Orcas at this moment

Predators

Being a robust animal with brute power and intelligence, they have very little natural predators, except for these:

1) Humans2) Some daring sharks e.g. tiger sharks who would probably only attack either the young or the

weak who is away from the pod3) Diseases e.g. bacterial and fungal infections, stomach ulcers, skin diseases, tumors, heart

disease and respiratory disorders

But even so, they are still very much exposed to cruelty that some of us don't even realise. Therefore, despite their highly predacious nature, when they are not being careful, they will still be food or forced to become entertainers to some.

Evolution and Intelligence

Like all hot-blooded mammals, Killer Whales went through an extensive period of evolution which started millions of years ago; transforming them from a land-lubber to an ocean dwelling creature. When ancestors of dolphins and other cetaceans first ventured back to the sea, they were all 4-legged. As time goes by, they evolved and developed a fish-like body shape and a pair of flukes, which came about from an ordinary mammalian tail. During this evolution process, ears, mammary glands and male genitilia all became internalized and got covered by a layer of smooth skin.

(Scientists says that the ancestor of a cetacean is a small deer-like creature)

*Flippers of a cetacean still contain 5 digits but they are concealed by muscles and skin*

As the skulls of these cetaceans change in shape, the nostrils move upwards which eventually become, what we now know, as blowholes. In addition, their eyes and ears changed to adapt to living underwater, making them more acute.

Physically, these dolphins have the second heaviest brain among marine mammals. Think about it, if they can be trained in captivity, it shows that they have the capacity to follow instructions and store information. To add on, there have been reports where these killers are seen to be deliberately teaching skills to their kin. With the passing of techniques from generation to generation, a culture is formed which ultimately leads to how they manage to live together without dominance struggles or family aggression. Can you see now, how intelligent they are?

Anatomy

Looking carefully at a Killer Whale (if you get to meet one, call me!), you will notice that their body is generally more robust than other dolphins. In other words, they were built to be tough yet elegant hunters. They have an acute sense of vision (in and out of the water) and smell which allows them to detect food and danger from far and by having a round head with no beaks, they can easily head-butt their prey, paralysing them instantly.

However, given their size, they are highly manoeuvrable and its mainly due to the tall, erect dorsal fin and large paddle-shaped

flippers which gives them stability when moving. In addition, they are propelled by a broad fluke (tail) which sets them off to high

speeds. However, an easy way to identify the gender of an Orca is to look at the dorsal fin. On a male, the fin is straighter, more erect and

can grow up to a height of 2m and on a female or a juvenile, the fin is curvier and will probably grow up to a height of 1m.

It is easier to determine the gender of the dolphin by looking at their fins because their private parts are hidden in their body as evolution made it easier for them to be more efficient in the aquatic environment. The female's genitoanal slit is near the belly with the mammary glands at each side of the opening. While the male's penis is in a slit, positioned about 1m from the back fin at the under belly.

*The pinkish male penis is called a “Seasnake*

And when they open their mouth you will see about 48-52 perfectly shaped conical teeth which curve backwards and can grow up to 10cm. With such a structure, the Orcas are able to have a stronger grip on their prey once they have them in their mouth.

*Have tastebuds and no sense of smell*

As you notice by now, knowing just their physical attributes is enough to acknowledge that these Killer Whales are indeed vicious predators. To give them more advantage, their body markings help them to remain camouflaged by the underwater environment. They are black on the sides and back and white on the under belly, with a distinct white patch right by the eye and a greyish patch behind the dorsal fin. Despite these fancy markings that screams “Incoming Predator!”, their skin is in fact very sensitive to touch which aids them in communication among themselves.

*Studies of closely related species suggests that the most sensitive areas are the regions around the eyes, mouth and blowhole*

Sometimes we forget that these beautiful Orcas are in fact mammals and that they retain certain attributes similar to humans, despite going through an extensive evolution process.

Firstly, they have to maintain a core body temperature of about 36.4 degrees celcius. The layer of fats beneath their skin (blubber), plays a huge role in maintaining body warmth. But when it gets a little cold, some blood vessels serve to re-circulate body heat back to their core area. And when it gets a little too warm, their flippers, flukes and dorsal fins serve as radiators; dumping heat back into the ocean.

Secondly, we should remember that Orcas can't breathe underwater, like us. Therefore, they must come back up to the surface after a few minutes to exhale quickly and inhale a new breath of fresh air. Metabolism rates of Cetaceans, such as Orcas, is relatively slow, so their bodily processes exert a minimal demand on the oxygen in the blood stream. During deep dives, their bodily functions that are unrelated to diving - e.g. Digestive system – slows down or even stop completely by the constriction of the blood vessels serving these functions.

Behaviour

Killer whales are very physical by nature be it during a hunt or a casual communication session. Some of their more common behaviour traits are:

1) Breaching – leaping out of the water

2) Tail slapping3) Spyhopping – poking their head out

of the water and looking around

Like any species of the animal kingdom, when it comes to protecting their family member, home or even that one female that they have been aiming for, things will get aggresive and sometimes ugly. Just like these members of the dolphin family. When they fight, they have a face-off by going head-to-head often producing clouds of bubbles while flaring their flippers, perhaps trying to make themselves seem bigger.

*The tittle of Killer Whale is both respectful and appropriate for an animal that has earned its reputation as the undisputed kings of ocean predators*

As we know by now, Orcas are considered dolphins and with that, comes the intelligence that most of us know dolphins posses. And this intelligence is being put to good use in all aspects of their underwater life. It is evident from how they hunt, sleep, feed and socialize among themselves; very different when compared to other animals in the ocean.

*Hunting

Orcas hunt cooperatively in a pod of about a few dozens to 40 killer whales, attacking bigger animals, such as a large Baleen Whale, from all sides and sharing the food with the other members; very much like a pack of wolves in the forest. In the attacking pod, the females, juveniles and bull (male adult) all work together to get their meal. While hunting for food, the big bulls sometimes patrol offshore while smaller bulls and youngters go about the shallow areas.

*Divers who have observed packs of killer whales in the sea say that the bulls seem to patrol the edges of the group shielding the females and the young*

How they hunt really shows their true colour of being known as an intelligent predacious mammal. But one thing's for sure, their intelligence are obvious when they are hunting. Firstly, they will even beach themselves to get that particular seal which just happens to be hanging out by the beach and near the coastline. Secondly, other than having the mindset to only hunt for food and not pleasure, these killers work together strategically to get that prey. For example, scientists have observe how they cooperate with each other in Antartica to get a seal/penguin that is stranded on a floating block of ice.

1) Having found a prey on a floating piece of ice, the Orcas will charge the ice moving it to the open sea while breaking that piece of ice into smaller pieces.

2) Then, upon signal, they will swim together to create a wave till the prey falls over into the water.

3) When in the water, and if needed, the killer whales will subdue the prey by bodily impact which will stun and automatically weakening them.

Sometimes, they will let the prey escape a few times or put the prey back on the ice so that the juveniles can learn how to attack their food. It has also been observe that the mother killers will push their young onto the beach to get then use to beaching for food; and all this while, the mom will wait at the back ready to pull her baby back into the sea if necessary.

*Sleeping

Yes, these giant Killer Whales do sleep or some would prefer to call it “resting”. Generally, they sleep by shutting down only one hemisphere of their brain at a time because we have to remember that they still need to breathe. If they are alone, they'll rest by staying near the surface exposing their dorsal fin, blowhole, and part of their head outside the water. However, if they are in a pod, they will form a tight circle, synchronizing their breathing and bodily movements. These killers will take several breaths at the surface then submerge and re-surface later on to take another breath and as the sleep becomes deeper, time spent submerged will increase. The advantage for sleeping in a pod is that sometimes, they can afford to have 2 Orcas on watch while the rest ofo them sleeps. However, with all these talk of sleep, during the killer whales's first few months of life, neither mother nor the calf sleeps.

*Social Structure

Complementing their high level of intelligence, these Killer Whales are very social animals. They live in a long-lasting matriarchal family groups which we know as pods (consisting of up to 30 individuals). And sometimes, they will form super pods by combining different groups of killers which can come up to about 150 Orcas.

Both the female and male babies of a mother will stay with her for as long as she lives. Even when the young continue to reproduce their own offsprings, they will

remain in that pod to build up multi-generational groupings with the original matriarch still being in-

charge of the pod. Take note that these killers are very protective of their young, the sick and the injured.

Generally, the adoslescent female will perform most of the care for the calves, just like a big sister.

*Whales will approach certain people, especially pregnant women*

Communication

When you watch a video involving dolphins you will notice that most of the times, other then seeing them sprouting from their blowholes, you'll hear things like clicks, whistles and pulses. That is how they communicte and each pod have their own dialect which distinguishes them from other pods; just like how we have hokkien, cantonese and mandarin. Therefore, during the days following a calf's birth, the pod will make these sounds more frequently to teach and get the baby used to hearing their own signature callings. But to start with, we must know how and why they produce these sounds. They use a method called “echolocation”; they will produce these sounds which can travel quite far and when the sound waves hit an object, it will bounce back to them giving them an idea of where their prey is and where they are going. Not only using echolation to communicate, they use it during the mating process as well.

Mating Process

Even though we are usually interested in the mating process of animals for various reasons, we don't realise how important this part of the life-cycle is in sustaining the survival of its own species. The Killer Whales have the intelligence to notice this, which is why they are polygamous but yet, mate only with other Orcas outside of their pod.

The females enter estrus or “heat” several times during a year. Nevertheless, even though the females can mate up till they're 40 years old, they are not able to do it every year. This is due a human's equivalent of having a “period” which is know as a Polyestrous cycle. The only difference is that there are no menstrual blood lost. The mating period can happen anytime but it is more common in the summer.

Firstly, they will usually begin with a prolonged set of playfulness.There is much tender rubbing in the beginning. However, this will escelate quickly to a more aggressive interaction later on. Secondly, the male will approach from behind at a perpendicular angle or in front of her to position himself in a belly to belly position. Thirdly, when the moment is near, the male will attempt to put his penis close to the female's central region. Lastly, he will internally fertilized the egg with an erection that can occur within 1 or 2 secs.

However, unlike us humans, these dolphins have 2 different types of copulation:

1) Penis inserted halfway – this act lasts no more than 10 sec even though ejaculation still occurs

2) Full penetration – these will usually last for more than 30 secs and it involves pelvic thrusts before, during nd after intromission (this process is repeated every 1-8 min and not necessarily with the same female)

*Young Orcas have been observed attempting to copulate with Orcas of both sexes, sharks and even turtles*

Reproduction

Killer Whales reach sexual maturity and are able to reproduce when the male is of about 6.7m (usually 15-21 years old) and when the female is about 4.9m long (usually 15 years old). Breeding all year-round, calves are born one at a time, tail first weighing about 130-150kg and are at least 2.4m long. Even so, they are born generally in warm waters and near the surface so that its easier for the calf to reach the surface to take its first breath, helped by its mother. Orcas have a gestation period of roughly 17 months and gives birth every 3-10 years.

Well i guess being a mammal, they have stronger motherly instincts than other ocean creatures. This is being assumed because if living conditions are adverse for the killer whales, they have the

conscience and instinct to not even mate at all, fearing for the safety of their calf once its being born.

*Even when calves are under close care attention from its mother and other pod members, it is estimated that up to 50% of wild-born orcas won't survive till the age of 1*

Habitat

As i have mentioned before, Orcas are the most widespread mammal, next to humans. With that in mind, they travel all around the world but these gorgeous killers don't make long seasonal migrations. These Orcas can travel up to 160km per day. They inhabit all the world's oceans and are the only member in the family to go from the equator to the colder waters of the polar regions; it has been observed that there are larger numbers of Orcas in the seas near the North and South Poles. Killer Whales generally prefer deeper waters but sometimes they will lurk around shallow waters and even venture in to bays, inland seas and estuaries.

Killers in Captivity

These giant mammals, no matter how much of a predator they are, they still belong to the wild. Putting them in aquariums and training them to perform for our own amusement can hurt them in so many ways, and this is evident in the Orcas that you see in parks i.e Keiko from the movie “Free Willy” and Tilikum of “Seaworld”, who have actually caused 3 deaths .

To begin with, by living in a tank, these dolphins have a decreased lifspan. Of the almost 200 taken into captivity since 1960, about 75% have not lived for more than 10 years. So far, only 2 have survived to live to their ripe old age.

In addition, these killer whales are higly social animals and putting them in tanks where they are sometimes forced to be solitary, forces them to be who they are not. Imagine if you are being kept in a room and are not able to see the other family members whom you know are in the room right next to you. Killers in captivity have been observe trying to masturbate themselves using ropes, jets of water or tank walls. Not only that, there have been reported cases whee Orcas in captivity kill their trainers and scientists which is assume to be due to mental stress.

Being kept in a tank does not only affect their mental stability but their physical growth as well. Killer whales in captivity doesn't have a tall, grandeur and erected dorsal fin. Instead, they have a droopy fin which drops to one side and this is because, without the need to travel fast, they don't use the muscles in the dorsal fin and over time, the muscles at the area become weak and are not able to hold up the physical epitome of a Killer Whale.

REFERENCES

1) http://www.rovinginsight.org/library/env-orca-elegant-hunter.php 2) www.wired.com/wiredscience3) www.animals.nationalgeoggraphic.com/animals/mammals/killerwhale4) www.afsc.noaa/nmml/education/cetaceans/killerphp5) http://www.dolphintrainer.com/killer_reputation.htm 6) http://www.enchantedlearning.com/subjects/whales/species/Orca.shtml 7) http://orca.dolphins-world.com/killer-whale-reproduction.html 8) https://en.wikipedia.org/wiki/Killer_whale 9) http://www.ehow.com/about_4570998_killer-whales-living-captivity.html 10) http://library.thinkquest.org/TQ0310067/Web%20Page/Adam.html 11) http://www.seaworld.org/animal-info/info-books/killer-whale/reproduction.htm 12) National Geographic- Citizens of the sea (wondrous creatures from the census of marine life) by Nancy Knowlton13) Illustrated Encyclopedia of Animals – Editor-In-Chief: David Burnie14) Ultimate Killers, The World's Deadliest Animals by Steve Leonard15) The Illustrated Guide to Marine Fish of the World by Amy Jane Beer & Derek HallKillers of The Sea (The Dangerous creatures that threaten man in an alien environment) by Edward R. Ricciuti, Photos by Jonathan Bird16) Cover picture taken from http://animals.nationalgeographic.com/animals/mammals/killer-whale/ by Gerard Lacz

Must Watch!

1) http://www.youtube.com/watch?v=B-nNT-e-BUE (mating)2) http://www.youtube.com/watch?v=5TcTw2a7FQo (birth)3) http://www.youtube.com/watch?v=p3xmqbNsRSk (hunting)4) http://www.youtube.com/watch?v=yFgrOJmT5Hs (socializing)5) http://www.youtube.com/watch?v=aJo89fHqq0U (boat chase)6) http://www.youtube.com/watch?v=NJwez7-3IKo (orcas resting)7) http://www.youtube.com/watch?v=4waz30EbI8o (attack at seaworld)

Written By: Noorin Najmi Nawi