Facts about Bottlenose Dolphins
The Bottlenose Dolphin is the most common species of dolphin, swimming at speeds of up to 30 km per hour. They also have a wide range of creative feeding techniques, with each population using a different method. Some even enlist the help of humans to catch their prey!
|Scientific name:||Tursiops truncatus|
|Diet:||Fish, shrimp and squid|
|Reproduction:||Give birth to one calf every 3 to 6 yrs|
|IUCN Conservation status||Least concern|
Bottlenose Dolphin classification and identification
Bottlenose Dolphins belong to a group called the Cetaceans, which includes all other dolphin species, as well as porpoises and whales. They are also members of Family Delphinidae, more commonly known as the small toothed whales. Members of this family are also often referred to as the true dolphins, although this includes species such as the Orca and the Short-Finned Pilot Whale. The word dolphin is adapted from the word delphis, which means ‘fish with a womb’.
The body and head of Bottlenose Dolphins are relatively wide. Their bodies can be dark grey to black, with a lighter colour underneath. They get their name from their beak, which is short and robust. The dorsal fin is tall and falcate.
Inshore and offshore Bottlenose Dolphins vary in colouration and size. The inshore Bottlenoses are smaller and lighter in colour than the offshore variety, while the offshore dolphins have smaller flippers.
Bottlenose Dolphin adaptations
Bottlenose Dolphins can reach speeds of up to 30 km per hour in the wild and will surface to breath two or three times a minute. They can hold their breath underwater for 7 minutes. Like most dolphin species, they communicate with each other using a complex system of squeaks and whistles; they can also use echolocation to track their prey. Bottlenose Dolphins have been known to leap or breach up to an impressive 4.9m out of the water!
Where do Bottlenose Dolphins live?
Bottlenose Dolphins are distributed worldwide in warm and tropical waters at latitudes from 45°N to 45°S. They occupy a wide range of habitats and are thought to be the most adaptable cetacean on Earth.
How big are Bottlenose Dolphins?
How long do Bottlenose Dolphins live?
Bottlenose Dolphins live for 40 -50 years.
What do Bottlenose Dolphins eat?
Bottlenose Dolphins eat mostly fish, shrimp and squid. They employ a wide range of feeding behaviors, with various dolphin populations employing different feeding strategies. For example, they may track their prey using echolocation, making up to 1000 clicking noises per second! Using a technique called crater feeding, they can use acoustics to detect prey species underneath the sand, which they then dig out using their rostrum. They may also smack fish with their flukes mid-water to stun them. They may also sometimes swim behind fishing boats hoping to get the leftovers.
Bottlenose Dolphins are also known to work cooperatively to catch schools of fish. In the tidal creeks of South Carolina and Georgia in North America, the species can be seen to use a technique called strand seeding, where the dolphins drive schools of mullet onto mud banks and then beach themselves in order to to catch their prey.
A fascinating relationship between Bottlenose Dolphins and humans in a town called Laguna in Brazil has also been reported. The dolphin will herd schools of fish into the nets of the fishermen. The fishermen will then throw down their nets at the right time following a signal from the dolphins. This relationship allows the fishermen to benefit from large catches, whilst the dolphins enjoy feeding on the disorientated fish that escape the net.
What eats Bottlenose Dolphins?
Sharks are the primary natural predator of the Bottlenose Dolphin. Bull Sharks, Tiger Sharks, Dusky Sharks and Great White Sharks commonly prey on this species.
Bottlenose Dolphin life cycle and reproduction
Bottlenose Dolphins reach sexual maturity at the age of 5-13 years in females and 9-14 years in males. Females usually give birth every three to six years. The gestation period is 12 months and calves are weaned at 18 to 20 months. There are records of females as old as 45 giving birth.
Conservation status: Are Bottlenose Dolphins endangered and if so why?
Bottlenose Dolphins are listed as being a species of ‘least concern‘ by the World Conservation Union (IUCN). This means that they are not currently at risk of extinction. However, many animals die as a result of bycatch through commercial fishing for other species, such as tuna, as they get tangled in the fishing gear and die. They are also still harvested directly in Japan and Taiwan. The species is also threatened by habitat degradation.