Dolphins will circle protectively around the weak members of the pod, and viciously attack anything that approaches in a threatening manner. And they can kill sharks. Most predators take one look, and then just swim away.

Like any animal, dolphins are sometimes victims to other species that seek to feed on them or get some other benefit from their body. But besides humans and other aquatic animals, they have a small number of natural enemies. In fact, some species do not have any.

In fact, the natural predators of dolphins kill very few specimens compared to the deaths of those predators who do not belong to their aquatic environment.

PREDATORS IN THEIR NATURAL HABITAT

Orcas (Orcinus orca) and large sharks dispute the title of “The most dangerous predator of dolphins,” and is that both, with their size and other physical characteristics and, of course, their natural need to feed on meat, find dolphins attractive.

Killer whales.
For some species, this mammal is the most deadly predator, and it is also a dolphin! Orcas feed on a wide variety of fish, mollusks, and crustaceans, but if they find a dolphin, they do not hesitate to grab it and feed on it. They usually catch the smallest individuals, the small species or the young.

Sharks.
It is common that sharks kill dolphins. Usually we hear that sharks are the mortal enemies of dolphins, but in reality, this is only because of their feeding instinct and not a particular “hate” or antagonism towards dolphins.

The smallest species are a common prey of bull sharks (Carcharhinus leucas), dusky sharks (Carcharhinus obscurus), tiger sharks (Galeocerdo cuvier) and great white sharks (Carcharodon carcharias). The most vulnerable dolphins are usually young and calves.

In some regions, sharks are the most dangerous group of predators that dolphins have to face, such as on the east coast of the United States. Sharks have species preferences; For example, bottlenose dolphins (Tursiops truncatus) are the favorite of the sharks mentioned above.

Killer whale – Apex predator.

Some researchers suspect that the attacks on dolphins do not always intend to kill for food, but only to defend what they consider their territory. However, scars on the skin of dolphins indicate that bites are evidence that sharks strike from below and behind the dolphins.

A surprising fact for many people, regarding the relationship between dolphins and sharks, is that they can tolerate each other perfectly in the same area and feed on the same bank of fish. Sometimes they completely ignore each other despite being a few meters apart.

But dolphins also defend themselves. Although they usually avoid sharks or flee from them, if necessary, they show aggression and show their most powerful defense system: The pod! When the group is together and alerted, sharks prefer to go away and avoid the pod which can quickly kill him.

Bottlenose dolphins sometimes attack these predators by striking their bodies with the caudal fins (tails). However, this defensive behavior is not very common with sharks.

THE MOST DANGEROUS PREDATOR

As with most species today, their most dangerous threat is the man. Sometimes, humans kill dolphins not because they are a source of food, but because they prey on the same fish species than humans. Therefore, many fishers have killed dolphins only because they are a competition for the fish.

In some countries, people eat cetaceans, including dolphins. In Japan, the meat of some species is seen as a delicacy and can cost up to $25 USD a pound.

In Peru and some other Latin American countries where the fish is becoming scarce due to overfishing or environmental conditions such as El Niño, desperate fishers have turned to catch dolphins and porpoises to sell them in fish markets.

Even more, there are some countries like the Faroe Islands, where killing and eating cetaceans, including dolphins, is a longstanding cultural tradition.

The presence of humans on Earth does not give dolphins many possibilities to survive. In the dynamic predator-prey, one side has to die so the other lives, but what happens when it is not about survival, but about business?

Without a doubt, humans are the biggest predator of dolphins. Their commercial activities endanger the life of these cetaceans directly and indirectly. Let’s look at some:

Dolphin Hunting.

The highest numbers of dolphin killings are in Asia, Africa, and South America. Dolphin meat is consumed in several parts of the world even though it is suspected to have high concentrations of mercury. Thousands of dolphins die every year, and the annual slaughter in Japan is infamously known. Sadly, dolphins put little or no resistance when massacred by humans.

Bycatch.

Tragically, the largest group of dolphins killed by man are those killed by accident or incidentally during large-scale fishing operations. Dolphins and other cetaceans that swim into these nets following fish, become entangled and drown when they can’t reach the surface to breathe or tear off parts of their body in their struggles to escape.

Dolphins die when incidentally caught by gillnets and trawl nets, without the intention to hunt these cetaceans.

Fishers have found that tuna swim beneath dolphins in high numbers, so they get caught when nets are deployed to catch tuna. Though the surviving dolphins are released, estimations indicate that at least 30 million dolphins have been killed in this way since the observations began in the 1960s.

Reduction of the habitat.

The construction of structures and the contamination reduces the number of healthy habitats turning some of them unsuitable. Intimately linked to pollution.

Pollution.

Every day millions of gallons of polluted water, toxic substances such as pesticides, heavy metals, plastic trash and hundreds of other hazardous materials are released into the ocean and the rivers. Their habitat becomes contaminated and causes illness and death. Especially, river dolphins are dangerously threatened by pollution because most of the rivers where the five river dolphin species live have high concentrations of pollutants.

Unintentional deaths.

Other unfortunate accidents are also deaths by collision against propellers or any other parts of boats.

References

https://en.wikipedia.org/wiki/Dolphin

https://seaworld.org/en/animal-info/animal-infobooks/killer-whale/diet-and-eating-habits

http://www.tandfonline.com/doi/abs/10.1080/13880291003705145

]]> https://www.dolphins-world.com/what-kills-dolphins/ Wed, 02 Oct 2013 20:05:01 +0000 http://www.dolphins-world.com/?p=360 Answer:

Besides the common predators like big sharks and occasionally killer whales, humans are the top killers of dolphin. If dolphins could figure it out, we would be considered their worst enemy.

The human activities that kill dolphins are fishing because dolphins get trapped in the nets while they try to catch tuna or some other species.

Also, human pollution is a huge threat for dolphins causing them to choke by eating debris or by damaging their senses and making them easy prey for sharks.

The excessive noise product of human activities in the ocean is also a threat to dolphins, as noise can kill dolphins or at least confuse them causing massive beach stranding.

Dolphins have a social structure which makes them swim and live together in small groups called pods or herds. (Names of animal groups).

The best defense mechanism that dolphins have is their social organization and the strong bonds between them. The primary purpose of pods, composed of about 12 dolphins is the protection of the members.

These groups make sharks, the only predator that dolphins have to face, to avoid approaching the pod.

When threatened or attacked, dolphins use their speed and agility hit predators.

Large species of sharks, eat small species of dolphins or calves. Also, occasionally killer whales eat small dolphins too.

The larger dolphins are apex predators which mean that they are at the top of the chain food.

The only predator that the small species of dolphins or calves have in the ocean are the large species of sharks.

Besides, there are no constant threats in the sea.

Sometimes, killer whales attack or eat dolphins, but this is not a standard behavior. In fact, killer whales belong to the family of oceanic dolphins too.

However, the most dangerous predators that dolphins have today are humans, and although we are not in the sea, we kill more dolphins (and sharks) than any other animal in the ocean.

killer whale factsKiller whales, also known as Orcas (Orcinus orca) are fascinating creatures that attract a great deal of attention from marine biologists, as well as the general public.

Orcas are Apex predators and adults do not have any other threat in ocean than humans, Research is always being done about Killer Whales, and new facts about their habits, socialization, intelligence, and travel patterns are discovered continuosly.

Here are the top facts that make this cetacean so unique to the general public as well as to the scientists.

• Killer Whales are one of the fastest creatures in the sea, traveling up to 30 miles per hour.
• Killer Whales are able to control the flow of blood to their hearts and brains, which keeps them from suffering from a lack of oxygen when they are deep underwater.
• Killer Whales eat up to 5% of their body weight each day. This averages out to over 500 pounds of food for each Orca.
• Killer Whales do most of their socialization within their own pods. However, pods do socialize with other pods as well.
• When breeding, Killer Whales do not breed with relatives. They only breed with killer whales that are not closely related to them within their own pods.
• Killer Whales are called “Killer Whales” because they feed on other dolphins and smaller whales, not because they kill people. They are also know as orcas.
• The only recorded instances of a killer whale attacking a human being have been of attacks by Orcas held in captivity. No killer whale that lives in the wilds has ever attacked a human being.
• Killer Whales eat up to 5% of their body weight each day. This averages out to over 500 pounds of food”.

• Every Killer Whale has a mark behind it’s dorsal fin that is totally unique. These marks are used by humans to distinguish one killer whale from another, just as humans each have their own specific characteristics that make our appearances different from every one else’s.
• Killer Whales use vocalization to communicate with each other, but each pod has it’s own unique ‘accent,’ which makes it easy for Orcas to identify members of their own pods.
• Pods of killer whales are found in all oceans in the world, but the greatest numbers are found in cooler waters.
• Killer Whales are actually dolphins. In fact, they are the largest dolphins in existence, and can be up to 30 feet or more in length, and weigh up to 12,000 pounds.
• Killer Whale brain is five times larger than a humans. They are very social, intelligent, and curious. killer whales brains that have been studied with microscopes have proven to be as structured and developed as the human brain.
• Killer Whales have very organized and complex social structures, and divide themselves in pods, which operate as human families do. They protect their young, ill, and injured within their pods.
• Killer Whales spend 60% of their time foraging for food. killer whales do not migrate, but they have been known to travel hundreds of miles to find fresh food that is in ‘season.’
• Life expectancy of a Killer Whale in the wild is 50 – 60 years for males, and up to 90 years for females, however, Killer Whales held in captivity have not lived longer than 30 years, and the average life expectancy for captive Orcas is only 20 years.
• Female Killer whales usually do not breed until they are between the ages of 12 and 16 years old. Their gestation period is 15 – 17 months, as opposed to 9 months for humans. They nurse their calves for up to 2 years. On an average, each female Orca that lives in the wilds will have approximately five calves during her lifetime.