Check out our zoo's dolphins

Tursiops truncatus

Weight:

200 kgs

Size:

3 meters
Mammals
Carnivore

Interesting facts

Tursiops truncatus

Phylum: Vertebrata

Class: Mammalia

Order: Cetacea

Suborder: Odontoceti

Family: Delphinidae

Genus: Tursiops

Scientific name: Tursiops truncatus

Conservation

Not evaluated

Discover the dolphins

Présentation

Worldwide range, except in fully enclosed waters. Quite common along the western shores of the Atlantic Ocean and in the Mediterranean Sea. This species lives in the open sea and near the coast. Description Length: 3 m (10 ft) on average Weight: 200 kg (440 lbs) Dentition: 88 conical teeth, approximately 7.5 mm (0.3 in) in diameter at the base. Body: very dark grey to white on the underside. The forehead, called the "melon," is part of its sonar system*. It breathes and produces sound through a blowhole*, its respiratory organ that replaces the nostril. It has a dorsal fin* of approximately 25 cm (10 in), a pair of pectoral flippers* and a very strong caudal fin*, which allows it to propel itself at very high speeds (up to 60 kph, or 37 mph). Its skin has the ability to "cut" through turbulent waters, through a system of up and down movements. This dolphin can jump very high out of the water. It can sound* up to 300 m (1,000 ft) and stay under water for about 20 minutes. *Glossary: Sonar: a method used for detecting things underwater by using sound waves. Blowhole: a hole on the top of an animal's head that is used for breathing. Dorsal fin: a rigid fin on the back of a fish or other aquatic vertebrate. Pectoral flippers: fins located on the sides of an animal. Caudal fin: the terminal fin of a fish (also known as the tail fin). Sound: to dive down suddenly (used by a fish or whale).

Social life Reproduction Communication

Social life

Dolphins either live in small groups of 10 or in groups of several dozens, led by a dominant dolphin. These groups seem to vary, depending on the season. In autumn and winter, the main group consists of mothers and their young. The males live separately for part of the year, but still stay close to the pod (school of dolphins). They hunt together, and then reconvene in small groups. Dolphins have a highly-advanced sense of family and a very sophisticated hierarchical order. Each group is led by a male or female that changes from time to time. Then, there are various ranks that can also evolve (e.g. a female with a calf moves up the social ladder). The "second" is often the one to keep watch and alert the group of any possible dangers. Dolphins are also capable of helping each other when in trouble.

Reproduction

Sexual maturity comes at 8 years for females and 10 years for males. A female expects a calf approximately every two years. After 12 months of pregnancy, the baby dolphin is born under water, usually caudal fin first to avoid asphyxiation. When a female is pregnant, another female accompanies her throughout her pregnancy. She helps protect the baby, who often swims between her and its mother. At birth, a baby dolphin is between 90 and 130 cm (3 to 4.25 ft) long and weighs 12 to 15 kg (26 to 33 lbs). The mother breastfeeds her baby for 12 to 24 months, although the calf starts to eat fish around 6 months old. Baby dolphins double their weight within two months, three times faster than humans, as the mother's milk is rich in fat and protein. They stay at their mother's side during the first few years of their lives. Knowledge of the evolution of baby dolphins has evolved tremendously, thanks to the reproductive studies carried out at the park.

Communication

Dolphins can see under water, even while swimming in the darkness of deep waters, at night or in muddy water. They use their sonar (detection system: echolocation) to get their bearings. For this, they send "clicking" noises that bounce off objects and return as echoes that tell them the distance, shape, texture, size and thickness of each object. Low frequencies are used to approximately locate the obstacle, while high frequencies provide more detailed information (up to a millimeter in thickness, for example). Accuracy is so high that a dolphin can distinguish two metals with different densities. Sounds vary from 200 to 300,000 Hz and are guided through the melon, which consists of fatty substances. Echoes are received by the ears and probably also by the fatty cavity in the lower jaw, which sends them to the ear canal. Dolphins do not have vocal cords and produce sounds through their respiratory system that have higher frequencies than the sounds produced by humans. Vocal cords are replaced by the air sacs located in the blowhole, as well as the muscles of the larynx. Dolphins produce two types of sounds: sounds for identifying themselves, the distinguishing feature of each dolphin (whistles and explosive sounds), and those used to get their bearings and interpret the environment (clicking noises). To communicate between members of the same group or between groups, they use whistling noises and each dolphin has its own "signature" sound that allows it to identify itself. The exact meaning of these noises is still unknown, despite the fact that dolphins' communication and sensory skills have been studied at the park for several decades now.

 

Diet Life expectancy Distinguishing features Threats

Diet 

Fish, crustaceans and mollusks. Life expectancy The common bottlenose dolphin is the cetacean that has been the most studied by scientists, both in the wild and in parks. Its life expectancy in the wild reaches 17.4 years, and is now 34.3 years in parks. Remember that the average life expectancy is the age at which at least 50% of a population is living. This is the only valid criterion for comparing two populations. Records of longevity observed in some dolphins may be higher. The oldest wild dolphin found off the coast of Texas is 44 years old, and the oldest dolphin living in a European park is 53 years old. His name is Moby, at Nuremberg Zoo in Germany. The major explanation for the difference between a natural environment and a park is that animals in a park are medically monitored and do not face the same threats that exist in the wild. Needless to say, a dolphin can live up to 40 or 50 years, but remember that this is not the average age of the population.

Distinguishing features 

Among the cetaceans, dolphins have a remarkable ability to adapt, which is why they are found in all major marine parks throughout the world, where they live in direct contact with humans and where their population prospers. Today, 2/3 of the population of bottlenose dolphins in European parks were born in the parks, and their population growth rate is 10%. We also hope that its unique ability to adapt will accommodate cohabitation with the increase of human activity at sea, which is not the case with many other species that are much more sensitive and weakened by these disturbances. Therefore, dolphins are not a species of great concern, in terms of conservation. On the list established by the IUCN (International Union for Conservation of Nature), the bottlenose dolphin is categorized as a "least concern" species.

Threats

There are eight common species of cetaceans in the western Mediterranean. The threats mentioned here affect all of them in different ways. The natural predators of dolphins are killer whales and sharks, but the greatest present-day predation comes from commercial fishing that is decimating the dolphin population in its nets. The most important threats that affect cetaceans, especially in the Mediterranean, include: Commercial fishing, which uses stationary nets or drift nets. Dolphins are not meant to be caught by these nets. However, if they are caught, they often drown, because they are unable to rise to the surface for air. Maritime traffic: an estimated 13,000 ships making 252,000 stopovers cross the Mediterranean every year. 18% of the world's maritime oil transport is concentrated in the Mediterranean. Dolphins are victims of accidental collisions and pollution. Whale-watching is starting to develop. It is a tourist activity that allows visitors to observe cetaceans in their natural environment. If done improperly or excessively, it disrupts the daily lives of animals and contributes to marine pollution.      Offshore powerboat racing, which is particularly popular along the coast during tourist season. It causes accidental collisions and contributes to marine pollution.

Conservation in the Mediterranean Protecting and respecting cetaceans

Conservation in the Mediterranean

Solutions are being organized to ensure the conservation of cetaceans, in an attempt to reduce these threats. Pelagos Sanctuary A marine protected area was created in 1999: Pelagos Sanctuary, between France, Italy and Monaco. This sanctuary focuses on providing researchers with the proper resources to learn more about animals, their environment and the impact of human activities. In addition, it is also responsible for raising public awareness and mobilizing those who use the sea, such as fisherfolk and boaters.

Marineland (through its research center, CRC) and its Foundation have been part of the Sanctuary's scientific and awareness committees since its creation. RNE (French National Stranding Network) The RNE has been rescuing cetaceans in trouble along the coast since 1972, and recording valuable biological and ecological data following those interventions. It is made up of scientists, volunteers and enthusiasts. Only those with a green card issued by the Ministry of Ecology are allowed to help beached animals. Some of Marineland's professionals have that authorization to intervene.

Protecting and respecting cetaceans

If an animal is in trouble - If you see a dead or stranded cetacean: do not touch the animal (it could be carrying a contagious disease) and inform the competent authorities: fire department (dial 18), RNE (in the Mediterranean: +33 (0)4 91 26 72 25). - If you see a live stranded animal or an animal in trouble: do not touch or try to handle the animal who could be hurt or hurt the person, avoid crowds and loud noises, which can cause stress, and call the RNE (+33 (0)4 91 26 72 25) or Marineland (+33 (0)4 93 33 55 77). To observe an animal at sea Whether on a whale-watching tour boat or aboard a private boat, please make sure to always follow the rules of conduct established by the Pelagos Sanctuary: Please observe animals from at least 5 miles offshore. Please stop your observation session if the animals appear to be bothered. Approaching is prohibited if a newborn is present. Please observe animals from at least 100 m (330 ft) away. Boats must approach animals from the side, from the back to the front (never directly in front). Please drive at a steady speed, no faster than the slowest animal and no faster than 5 knots. Only one boat is allowed in the observation area at a time. Please stay no longer than 15 minutes.  It is prohibited to swim, touch or feed the cetaceans.