When people think of a dolphin, they usually have the image of a bottlenose dolphin in their heads. These beautiful and intelligent dolphins are therefore loved in marine aquariums and dolphinariums all over the world. Bottlenose dolphins are also often seen in the wild. But how does the bottlenose dolphin actually live? What does a bottlenose dolphin eat, and where exactly are these animals found?
Taxonomy and types
The bottlenose dolphin, like all other cetaceans, is a mammal: unlike fish, it has lungs, and the animal has to surface from time to time to breathe. Bottlenose dolphins belong to the order of the marine mammals (Cetacea) and to the suborder of the toothed whales (Odonteceti). Bottlenose dolphins belong to the family of the true dolphins or the sea dolphins.
Until the end of the last century, all bottlenose dolphins were considered to belong to the same species, namely the (Tursiops truncatus). Only after 1998 were three separate species identified: the bottlenose dolphin (Tursiops truncatus), the bottlenose dolphin (Tursiops aduncus) and the Burrunan (Tursiops australis). At first it was thought that the last two species were subspecies of the bottlenose dolphin, but it turned out to be actually different species.
Appearance and appearance
The bottlenose dolphin is a steam-lined dolphin; Unlike, for example, orcas and porpoises, bottlenose dolphins have a clearly defined snout. The animal has a gray back and a light gray to white belly. The flippers and dorsal fin are pointed.
An adult bottlenose dolphin can reach sizes of up to four meters and a weight of up to 500 kilograms, although most animals are between two and a half and three and a half meters. Males are generally slightly larger than females.
Bottlenose dolphins generally live in groups of around 15 animals; they are occasionally observed in groups of a few hundred to sometimes a thousand animals. A solitary bottlenose dolphin is also observed every now and then.
Distribution and habitat
Bottlenose dolphins are a very common species; they can be found in almost all waters with the exception of the seas around the poles. Until the 1960s bottlenose dolphins could even be found in our Wadden Sea; after the construction of the Afsluitdijk, the bottlenose dolphin disappeared from Dutch waters. In 2004 a population was again observed in the Marsdiep, between Texel and Den Helder. The animals were not seen here later. Although the bottlenose dolphin has disappeared from Dutch waters, the species does occur in the North Sea. Especially in the Channel and along the Scottish East coast the animals are regularly observed.
Bottlenose dolphins as a species have no clear preference for deep or shallow waters; there are groups that mainly live in coastal areas, but also groups that feel more at home on the open sea. The so-called “offshore” types differ somewhat in appearance, lifestyle and diet from their counterparts in deeper waters.
Food
Dolphins are fish eaters; different types of fish, including herring and mackerel. In addition, they sometimes also eat small octopuses and other mollusks.
Underwater vision is often quite cloudy and bottlenose dolphins have quite poor eyesight. Bottlenose dolphins therefore use echolocation: they can determine the location of their prey by means of high tones that they emit.
Bottlenose dolphins often hunt in groups, surrounding a school of fish with a number of dolphins. Some animals swim clockwise; other animals swim counter-clockwise so that the fish cannot escape. Then the bottlenose dolphins attack the school of fish at the same time with a number of dolphins. Another common hunting technique is to chase a fish (or a school of fish) towards a sandbank or shoreline. There have even been cases of bottlenose dolphins helping fishermen catch fish in this way; for a reward, the dolphins chased a school of fish in the direction of the fishermen.
Bottlenose dolphins in captivity
Bottlenose dolphins are very popular with the general public and of all cetaceans are the most often kept in captivity. Due to their intelligence, the animals are easy to train; the supple and lithe animals can show the most spectacular arts.
Dolphins have not been kept in captivity for very long: it was not until the 1960s that dolphinariums and marine aquariums in which dolphins are kept on the rise. The first dolphins to be kept in captivity came from the wild: today most bottlenose dolphins in dolphinariums are born in captivity.
In the Netherlands dolphins can be admired in the Dolfinarium in Harderwijk. A small group can be found in the dome-shaped DolfijnDoMijn that provides daily shows; there is also the dolphin delta, where a larger group of animals live under natural conditions.
Flipper
Flipper was a television series from the 60s of the last century. In the series, a bottlenose dolphin named Flipper played the lead role. In fact, Flipper was not just one dolphin; the role of Flipper was played by no fewer than seven different dolphins.
The Flipper series has contributed to the interest and interest in dolphins worldwide. Several dolphinariums, including the Dolfinarium Harderwijk, were founded around this time.