The dusky dolphin is a small cetacean that belongs to the Delphinidae family and the genus Lagenorhynchus, which also includes other five species.

It has a distribution limited to the southern hemisphere of the planet, with subpopulations scattered throughout the southeast and southwest Atlantic and Pacific oceans, including waters of Tasmania, southern Australia, New Zealand, the Chatham and Campbell Islands, South America and the Falkland Islands.

It also dwells around oceanic islands such as Tristan da Cunha, a British archipelago in the South Atlantic. Some of the countries that have dusky dolphins in their waters are Australia, Argentina, Chile, New Zealand, Peru and South Africa.

They sometimes stay close to bottlenose dolphins, but there is no evidence of interaction between the two species, unlike Risso dolphins, with whom they share feeding areas or with common dolphins that show some social contact.

This dolphin stays close to the coast, but unlike others, the coasts where they inhabit do not have warm waters. It is common to observe this cetacean on continental platforms and slopes where the waters are cold, and the currents have low temperatures, more or less of 10 to 18 Celsius degrees. The observed range of this species suggests that it limits to depths less than 200 meters and about 200 nautical miles away from the coast.

Its range of distribution goes hand in hand with the habitat that can provide them a great abundance of prey, among which is the anchovy that is found very close to the surface in shallow waters, and benthic creatures such as squids, hake and various types of fishes.

The cold habitat in which it lives does not deter humans from harming this species. Years ago, its capture was very constant in New Zealand, Peru and Chile mainly. Now, this has diminished, but its population situation, and therefore, its current state of conservation, is unknown.

In the vast ocean, all creatures are vulnerable. Bottlenose dolphins are cetaceans that rarely become prey, thanks to their size, their intelligence, the use of echolocation and their level of socialization that gives them a significant advantage by staying in groups and intimidating their opponent. However, two predators will take the smallest opportunities to feed on dolphins: killer whales and sharks.

We know that the killer whales are expert hunters, especially when they hunt in organized groups. Although there are few documented cases, these animals that are the world’s largest dolphins, attack other species of smaller dolphins, mainly young, newborn or sick. To do it they separate the mother from the calf, making impossible to the latter defend its offspring.

However, a group of orcas does not feel intimidated by a large pod of dolphins. Although there are no records of this kind of attack to bottlenose dolphins, there are videos where a pod of killer whales approaches aggressively to groups of dolphins of other species, and as if they were seals, they beat them and throw them into the air until they are stunned and finally feed on them. Several types of dolphins suffer this kind of aggression, and the bottlenose dolphins are likely part of this list.

Regarding sharks, the most dangerous species for members of the genus Tursiops are the largest: tiger shark, sand shark, bull shark and, of course, the great white shark. It is not uncommon to observe dolphins with scars from shark attacks, which means they are not easy prey and their escape techniques often help them survive.

A study conducted in Shark Bay, Western Australia, revealed that 95 of 128 bottlenose dolphins analyzed showed scars from shark bites, mostly from tiger sharks. The frequency of new body marks and the high attack rates suggest that bottlenose dolphins are at risk in this locality more than in other parts of the world.

A few cases with rays are known. Although they are not dolphin predators because they have a diet based on small fish, mollusks, and plankton, the trauma and infections they cause with the sharp edges of their tail sometimes become deadly.

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There is an ongoing debate about why dolphins jump out of the water.

Scientists think about different reasons for this behavior.

Among them, some believe that dolphins jump while traveling to save energy as going through the air consume less energy than going through the water.

Some others believe that jumping is to get a better view of distant things in the water, mainly prey. So, in this way, dolphins jump to locate food or food related activity like seagulls eating or pelicans hunting.

Other explanations suggest that dolphins use jumping to communicate either with a mate or with another pod as they can hear and interpret the splashes.

Some people even think that dolphins jump for cleaning, trying to get rid of parasites while jumping.

Finally, some scientists believe that they are only having good fun, as playing helps to keep senses at their best.

There is not a single scientific explanation about why dolphins jump in the air.

Some of the theories include:

– Dolphins jump in the air to save energy as it consumes less energy traveling through the air than through the water.

– Dolphins jump to locate some other pod or to find food by looking at the water for signs of food like feeding birds or any other indication of food location.

– Dolphins do it to communicate to other dolphins or pods to hunt together or for another purpose.

– Dolphins jump only for fun.

– Dolphins jump to get rid of parasites.

While bottlenose dolphins do not migrate in the summer, they move to different locations due to the change in water temperatures, which cause their common prey to move from one place to another.

In summer bottlenose dolphins do not have a particular place to go, they tend to travel and move around for food back and forth.

However, it is important to mention that dolphins travel a lot looking for food, covering sometimes more than 4,000 km in a month.