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.

An ecological niche is a role or way of life that an organism takes within its habitat and how it adapts to meet its basic needs to survive and proliferate, through a set of conditions, resources, and interactions with others.

Two organisms can not have the same niche, as they would compete for the same resources, which would cause only the strongest to survive, leading its opponent to extinction. In nature, although there are some species whose niches overlap, they have different options that make them easier to satisfy their daily requirements.

In this sense, the niche of Orcas is quite variable. The extensive distribution of this species makes that its populations have different cultures that have evolved according to their environment. Some even think that new unidentified subspecies are wandering in the oceans right now.

The niche of these cetaceans differs more clearly in their diet. For example, North Pacific killer whales that live south of Alaska, Washington, and British Columbia and are known as residents rely on fish and squid. In contrast, orcas called transients and whose range of distribution overlaps with residents, but without interbreeding, have a diet that is based primarily on marine mammals.

The interesting thing about killer whales is that they are not limited by salinity, temperature or depth since they have the capacity to move through waters of different latitudes, the open sea or reach coastal areas with depths of only a few meters.

The five ecotypes of Antarctic killer whales and three of Pacific killer whales differ considerably in diet habits, habitat, behavior, and social structure. Therefore their niche entirely depends on the ecotype.