When it comes to predator/prey relationships the killer whale is an apex predator and isn’t known to have any natural predators except for humans, parasites and diseases which can have a significant affect on a killer whales health.
Lacking any natural predators of their own these marine mammals are able to freely hunt and kill other oceanic creatures without the fear of being hunted themselves.
Like other dolphin species (killer whales belong to the dolphin family) they are known to consume fish, squid, octopus, crustaceans and cephalopods.
However unlike other dolphin killer whales also hunt other marine animals such as seals, sea lions, penguins, sharks and even other cetaceans which include whales, dolphins (killer whales do eat other dolphins) and porpoises.
Despite being natural predators that eat other living mammals killer whales do not appear to show any interest in regards to eating people and there are no known cases of a killer whale consuming a person.
There are however a few cases of people being attacked in the wild, but these attacks are extremely rare and once the killer whale realized it wasn’t their typical food they gave up.
When hunting for food these massive creatures can often be seen traveling in packs or pods using organized hunting strategies to isolate and immobilize their prey while minimizing their own chances of sustaining injuries.
For example when hunting sharks one or several killer whales may attempt to distract the shark while another killer whale sneaks up from behind or underneath the shark to ram it and flip it over.
Once the shark is flipped over it becomes shocked and unable to attack allowing the killer whales to attack their prey without the fear of being attack themselves.
When hunting fast and agile prey such as dolphins killer whales will work collectively to tire the dolphin out until it is unable to swim away fast enough to escape.
They have even been spotted sneaking up to the beach or an iceberg using stealth and then quickly leaping out of the water and on to the sand or iceberg in order to surprise their prey and grab onto it before it can react and escape.
While these marine mammals are not hunted by other animals killer whales are well aware of the fact that some of their prey may try to defend themselves which could lead to permanent injuries such as injured fins or the loss of an eye.
Because of this fact killer whales are very cautious and methodical about their hunting methods, so that they can maximize their success rates while ensuring their safety.
Part of what makes killer whales such successful hunters and defenders is the closely knit packs or groups they travel in and rarely separate from.
Killer whales are very family oriented and when one killer whale successfully captures its prey the food is often split between family members and close friends.
Like with humans the bonds of killer whales can last a lifetime.
These close bonds allow killer whales to work together when foraging and protect one another from potential threats from sharks and other marine animals that may put up a good fight when being attacked.
While the killer whale is an apex predator it doesn’t mean other species will lie down and give up.
In fact there are a number of other species that will fight back to protect themselves and their families.
For example female sperm whales are known to occasionally face threats from hungry killer whales looking to steal their small children away for food.
In order to protect their children the female sperm whales may form a circle around the child using their flukes to hit any potential predators trying to enter the circle.
It has been said that the amount of power that can be generated by their flukes is enough to seriously injure a lurking predator and may even be lethal.
Sharks are also likely to put up a fight when being attacked and if possible may attempt to latch onto a predator and trash back and forth in order to wound and injure the predator.
With that said there is only a small percentage of shark species that are known to hunt large prey and form a proper defense.
Non traditional predators
As stated earlier the killer whale doesn’t face regular threats the way other ocean animals do, however they are not invincible and can become harmed, ill or killed by other threats such as humans, parasites and disease.
When it comes to being harmed by humans the killer whale can be affected either directly or indirectly and intentionally or unintentionally depending on the situation and interests of those involved.
Unintentional threats may include:
- Over fishing
- Fishing equipment
- Water contamination/waste
- Oil spills
- Noise pollution
- Ship/boat strikes
Intentional/deliberate threats may include:
- Illegal hunting
- Unauthorized capture for research
- Live capture for aquariums in some parts of the world
Unintentional threats such as over fishing can cause serious issues for killer whale pods that are reliant on certain food stocks (particularly fish) for their survival.
Having to compete with with commercial fishing companies for fish and other sources of food may force killer whale pods to either relocate or face starvation.
In addition to threats from over fishing killer whale pods may also be harmed by the fishing equipment that is used or discarded such as fishing nets (intended for fish) and fishing lines.
Boat strikes from passing boats or ships may also cause serious harm to nearby killer whale populations, especially in highly commercialized areas.
Other threats include contamination from waste and harmful chemicals, oil spills from large ships and/or oil refineries and noise pollution caused by loud aircraft, explosives, sonar and other noisy equipment.
When it comes to noise pollution it is believed that loud man made sounds can affect the killer whales use of echolocation and may even cause brain hemorrhaging.
Extreme cases may lead to beached stranding’s and decompression sickness (Dysbarism), which is less common in marine mammals but still possible when rising to the surface to quickly.
Intentional threats such is illegal hunting, unauthorized research capture and live capture for aquarium display are also known causes that can contribute to the death of killer whales.
Although these situations exist they tend to be less common among killer whales than other species of whale/dolphin.
In fact illegal hunting for example is much less common among killer whale populations than among large baleen whales and some dolphin species as they may be both harder to capture and less financially rewarding.
When it comes to other species both whales and dolphins are known to be hunted for their meat which depending on the country may be sold for a premium in certain restaurants or grocery stores.
Dolphin meat has also been found in cans of tuna as well as other fish related products to be used as a substitute for tuna.
While these threats may be less significant to killer whales than over fishing and pollution/contamination they can still have an affect on certain killer whale populations/pods with the added affect of being an intentional act.
When it comes to parasites most parasites have little affect on healthy killer whales, however those that are sick or weakened may be further affected by living parasites that are host to their bodies.
Flukes, roundworms and tapeworms have all been observed feasting on killer whales as well as fungal and bacterial infections.
As with all animals killer whales can face threats from diseases and bacteria that can have dire consequences on their long term health.
In some cases these diseases may even lead to death.
Killer whales have been observed with a number of different diseases and medical issues such as hodgkin’s disease, heart disease and skin diseases as well as stomach ulcers, tumors and respiratory disorders.
In fact reports of killer whales dying from the West Nile virus and St. Louis encephalitis have been recorded.
Interestingly these cases have only been observed in captive killer whales suggesting that their lowered immune system may have been what led to their deaths.