Bottlenose Dolphin (Tursiops truncatus)Whale Web Header

 

 

Quick Facts

Family:
 Delphinidae
Genus species:
 Tursiops truncatus
Size:
 1.9-3.9 m
 6.25 - 12.5 ft
Weight:
 150-650 kg
 330-1,435 lb

    Surfacing to breatheBottlenose dolphins are probably the most easily recognized type of dolphins throughout the world, made popular by the TV show "Flipper" and marine parks. They are the ones most commonly seen performing at facilities that house whales and dolphins. These dolphins always appear to have a friendly look, since their jawline resembles a fixed "smile." Their behavior is not always friendly, however, and they have been seen attacking other cetaceans, even flipping them out of the water with their blows.

    Bottlenoses can be found in both the Atlantic and Pacific ocean, but are slightly different from each other. Atlantic bottlenose dolphins are the ones most often seen in captivity, and are smaller than their Pacific counterparts. Pacific bottlenoses can reach lengths of up to 3-4 meters, with a birth length of 1-1.3m. On the other hand, Atlantics are typically around 2.5-2.6 m when fully grown. Bottlenoses are even seperated into two more groups after that - some prefer to stay farther offshore, while other groups like to stay along the coastline, and may even travel a little ways up rivers. These two groups do not seem to mix.

    A typical bottlenose dolphin will be mostly slender in shape. Their dorsal fin is located in the middle of their back, and they have slender pectoral fins. Their rostrum, or beak, is very definite, giving them the name "bottlenose". Colors in individuals can vary greatly. Albino bottlenose dolphins are rare, but sometimes a dolphin can be very pale, almost appearing to be an albino. Contrastingly, certain individuals can be very dark, almost black, and there are many shades of browns and greys inbetween, with some individuals appearing as bluish-grey in appearance. A bottlenose dolphin usually has a darker colored back, with the coloration on their underside sometimes significantly lighter in shade.

    Bottlenose dolphins live in family groups called pods. Sometimes a pod will consist mostly of females with their offspring, with males joining occasionally to travel with them, sometimes to mate. Lone bottlenoses are typically male, though two males close in age sometimes will be "buddies", constantly traveling together and working cooperatively in hunting and mating with females. This relationship may last their whole life. Some bottlenoses have a "home range" that they will stick to, never leaving certain bounderies they have somehow set. Yet others might travel without a set range. Each area of bottlenose dolphins have pods that have behaviors that can greatly differ from pods in other areas.

    Has anywhere from 76-100 teeth!The gestation period for a bottlenose dolphin is about 12 months, and a young dolphin will stay close to its mother and nurse anywhere from a year to a year and a half, though it may also eat or play with food offered by its mother at several months of age.

    As a young dolphin grows, it will learn to eat a great variety of foods from different species of fish to shrimp or squid. A bottlenose has anywhere from 76 to 100 sharply pointed teeth. These teeth aren't made for chewing, but rather grasping and tearing.

    Bottlenoses are very playful animals, and can often be seen riding at the bow, or front, of a ship. They use the pressure coming off the ship to help carry them through the water, putting hardly any effort into swimming. One can sometimes see them darting back and forth in front of a ship as they bow ride. Bottlenoses are also known to surf waves, and can often be seen riding the curl of a wave, then swimming back out to catch another one in. They are very active in the water, able to leap high into the air, a behavior used extensively in marine parks.

    A great deal of research has been done with bottlenose dolphins in captivity, and scientists have found that they have a understanding of complex language, and can understand the difference between a sentence using the same words, but having different structures. For example, they can understand that the sentence "Take the ball to the hoop" is something different than "Take the hoop to the ball." They can also understand positives and negatives. If a dolphin is asked if a certain object in the pool, they can answer yes or no by pushing two different paddles.

    They have also discovered that a bottlenose dolphin can dive to a depth of at least 1,550 feet. They are able to do this without encountering a deadly condition known as the "bends" because at that depth, their flexible ribcage collapses.

    Also, bottlenose dolphins have been found to have a very sensitive method of detecting objects in the water, even when they can't see them. Bottlenose at Sea World, FloridaThey do this through a process of sending out pulses of noise and bouncing them off objects, in what is called echolocation. With this method, a dolphin can "see" a tiny object in the water, know how far away it is, and what material it is made of. These noises are rapid clicks, sounding something like a creaking door.

    Bottlenoses have a few dangers in life. Sometimes orcas will hunt them, or perhaps one may be attacked by a shark, though it seems that sharks largely tend to avoid dolphins all together, and both co-exist peacefully. Sadly, their greatest threat are humans, as they may be killed by getting entagled in drift nets and drowning, or being killed in tuna catches. Pollution is also a factor harming them. There are a lot of efforts to help save dolphins, such as new methods of fishing to prevent dolphin fatalities, but a lot more can still be done.

 

last updated 7/15/00
Whale Web copyright 1996-2000
Questions? Comments? Corrections?
Please send us mail!
kasatka@whale-web.com
keet@whale-web.com