Bottlenose dolphins are present in most oceans and seas of the world and adapt quickly to several types of habitat.

Their thermoregulation capacity allows them to live in waters ranging from 10 to 32 degrees Celsius, which includes temperate, tropical and subtropical areas of the Pacific, Atlantic, Indian Ocean, as well as the Mediterranean Sea and the Black Sea between Europe and Asia. The regions that avoid are the polar zones, but some individuals move through the north of Europe, whose waters have low temperatures.

In the Pacific, their distribution range is from northern Japan to Australia and from southern California to Chile in the eastern Pacific Ocean including all the vast area in the middle.

In the Atlantic ocean, they dwell from Nova Scotia to Patagonia in the West and from Norway to South Africa in the East including all the eastern coast of the United States, and the Gulf of Mexico.

Bottlenose dolphin habitat includes bays, open waters, coastal areas, lagoons, estuaries, tidal areas and shallow areas. They even venture occasionally into some rivers.

The other bottlenose species, the Indo-Pacific bottlenose dolphin, is also distributed in tropical and subtropical areas in specific regions of the ocean. This dolphin inhabits from western South Africa to Japan, including eastern and western Australia and places such as the Red Sea, Persian Gulf, Solomon Islands and the Indo-Malay archipelago.

The Indo-Pacific dolphin lives near the coasts of continental shelves, at depths of less than 300 meters and around oceanic islands. It frequently visits estuaries and coral reefs where fish banks thrive, and a significant amount of cephalopods live. Therefore it tolerates salt water and brackish waters.

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.

(Tursiops Truncatus)

INFORMATION AND CHARACTERISTICS.

No other dolphin species is known, studied and beloved in the world more than the bottlenose dolphin. Charismatic, playful and intelligent are some of the words often associated with this dolphin. And it has been presented in several manifestations of human culture such as films, literature, television, and much more, but not only in modern times, since the age of the Greek civilization, there are records of interaction with this cetacean.

Its presence in aquariums and dolphinariums is also very common which makes it the most familiar and recognized species of dolphin.

HOW DO THEY LOOK? PHYSICAL CHARACTERISTICS.

Morphology.
The bottlenose dolphin has a fusiform and robust body, extremely efficient for keeping a fast speed when swimming. Its snout is short but thick and well defined which gives it the colloquial name. Its dorsal fin, located in the center of the dorsal area, is big and curved.

Order: Cetacea
Family: Delphinidae
Genus: Tursiops

Weight and size.
Males are somewhat larger than females. In adulthood, adults measure 2 to 4 meters and weigh between 150 and 650 kilograms.

Skin Coloration.
Its skin is dark gray in the dorsum, a bit lighter gray in the sides and light gray color in the ventral region which sometimes is whitish.

Bottlenose dolphin – Tursiops truncatus.

WHERE DO THEY LIVE? DISTRIBUTION AND HABITAT.

The bottlenose dolphin dwells in tropical, subtropical and temperate waters between latitudes 45° north and 45° south. This cetacean is native to the Pacific Ocean, the Atlantic Ocean, the Indian Ocean and the Mediterranean Sea. Although they do not usually live in polar areas, it can be present in northern Europe.

It is a very adaptable dolphin because it has a great variety of habitats either on the open ocean and near the coasts. It has the possibility of living in bays, estuaries, coastal areas and low-depth places as well as the high sea.

WHAT DO THEY EAT? DIET AND EATING HABITS.

The bottlenose dolphin has a vast diet based on the consumption of fish, cephalopods, and crustaceans. But, given their extensive and differentiated distribution, their feeding habits vary depending on the region they inhabit and the habitat where they dwell.

Bottlenose dolphins living in high seas feed on several species of fish and pelagic squids, while dolphins near the coasts consume fish and benthic invertebrates found in coastal areas. The diet of any dolphin depends on the availability of prey in the environment.

Bottlenose dolphin range

Some of the common prey that this dolphin consume are:

Stardrum (Stellifer lanceolatus).
Atlantic Mackerel (Scomber scombrus).
Hake (Merluccius merluccius).
Blue whiting (Micromesistius poutassou).
King mackerel (Scomberomorus cavalla).
Atlantic croaker (Micropogonias undulatus).
Atlantic brief squid (Lolliguncula brevis).
Squid of the genus Loligo.

Their prey has a small size, measuring between 5 and 30 centimeters in length. They can feed individually but often cooperate with others to hunt, especially when dealing with a large school of fish. In these cases, the dolphins coordinate to chase or herd the bank swimming very agile to keep the school together and take turns to swim through the school feeding very efficiently; Some other times, they use their echolocation to find or stun prey.

Once they have found food nearby, they catch it and holds it tightly with their teeth. To kill it, dolphins shakes it in the air and sometimes hit the body against water or strike it with its tail. Then swallow it entirely, without using the teeth to chew.

These dolphins also feed in unusual ways: if they have the opportunity, they follow the fishing boats to consume discarded animals or take captive fish in the fishing nets.

HOW DO THEY BEHAVE? BEHAVIOR

Probably you have seen how this dolphin confidently approaches humans and jumps in the air. The bottlenose dolphin is very common in dolphinariums due to its excellent adaptability and relatively easy training. It is an intelligent animal, and most knowledge about dolphins is the result of research made on this species.

Their pods are socially open, made up of 2-20 individuals, except for some occasions when they group into super pods with hundreds or even thousands of them. A society of bottlenose dolphins contains a group of mothers with their offspring, a group of young individuals and a group of adult males.

Their friendly and empathetic behavior is evident when they help buddies unable to swim, and this is more manifest in mothers who have lost calves. The bottlenose dolphin partners with several species of dolphins and cetaceans and has even interbred successfully with the false killer whale (Pseudorca crassidens).

Active and playful, it can perform a large variety of movements and stunts: it strikes its tail against the water, rides the bow waves created by boats and jumps out of the water full of energy.

Bottlenose dolphin jumping in the aquarium show.

HOW DO THEY REPRODUCE? MATING AND REPRODUCTION.

The sexual maturity of this polygamous dolphin varies according to the place where it lives, but the age ranges between five to ten years for females and 8 to 13 for males. However, males usually mate for the first time at around 20 years old.

Usually, males create alliances to look for receptive females in heat. Once they found possible partners, they try to attract them by arching their back, touching their body and making sounds. They mate joining their bellies in the same direction.

The gestation period lasts about 12 months, after which the female gives birth to one offspring any time of the year, this can happen every 3 to 6 years.

WHAT IS THEIR CONSERVATION STATUS? THREATS AND CONSERVATION.

Conservation status: “Least Concern.”

The bottlenose dolphin has a conservation status of “Least Concern” on the Red List of the International Union for Conservation of Nature notwithstanding the following continuous threats:

– Bycatch in gillnets, trawls and draft nets.
– The intentional catch in some countries for human consumption or bait.
– Contamination of its habitat.
– Catch for keeping in captivity (aquariums and dolphinariums)
– Noise pollution.

The Marine Mammal Protection Act of 1972 protects the life of this species, as well as the Habitats Directive of the European Union. In Bulgaria, Romania, Turkey, its hunting is prohibited and included in Appendix II of CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora) as a species in need of regulation on its trade.

Bottlenose Dolphin Infographic!

(Click for expand)

References

http://www.iucnredlist.org/details/22563/0

William F. Perrin, Bernd Würsig, J.G.M. ‘Hans’ Thewissen. Encyclopedia of Marine Mammals. Academic Press, 2009. Page 249.

Jefferson, Webber, Pitman. Marine Mammals of the World: A Comprehensive Guide to Their Identification. Academic Press, 2015. Page 238.

http://www.cms.int/reports/small_cetaceans/data/t_truncatus/t_truncatus.htm

http://www.sms.si.edu/irlspec/Tursio_trunca.htm

Wild Bottlenose dolphin

Bottlenose Dolphin – Tursiops truncatus

Tursiops Truncatus

Image Courtesy of: Rene at da.wikipedia

A Bottlenose Dolphin at play in Perdido Bay, near Orange Beach, Baldwin County, Alabama in 2006

Image Courtesy of: Altairisfar

//www.youtube.com/watch?v=iEvV2iycNgw

Cute Baby bottlenose dolphin

Bottlenose Dolphin (Tursiops truncatus) picture