Intelligence: The intelligence of Amazon River dolphins has not been extensively tested. Their encephalization quotient (the ratio of brain mass to body weight) compares favorably with that of the bottlenose dolphin (Tursiops). The gray dolphins tend to be more "cautious" than the pink dolphins, perhaps because of their small size and very delicate skin. On the other hand, Inia is known for its highly developed sense of curiousity and it rapidly associates with man in a variety of serious and playful ways.
Pink Dolphins

Bottlenose Dolphin (Tursiops truncatus)

Bottlenose Dolphin (Tursiops truncatus)
Pink Dolphins

Facts Bottlenose Dolphin
Because of their propensity for coastal areas and their popularity in marine parks, bottlenose dolphins are one of the most well-known and recognizable cetaceans. Bottlenose dolphins are relatively large, streamlined animals with gray coloration and a prominent "beak." They are known for their acrobatic activity.

Bottlenose dolphins can grow to 8-12 feet and weigh up to about 1,400 pounds. They have a gray back that ranges from light to dark gray and a lighter underside. Like other Odontocetes, bottlenose dolphins live in pods, although the structure of these pods may be looser than that of other toothed whales, like the orca.

Bottlenose dolphins are considered one of the smartest animals on the planet.

* Kingdom: Animalia
* Phylum:Chordata
* Class: Mammalia
* Order: Cetacea
* Suborder: Odontoceti
* Family: Delphinidae
* Genus: Tursiops
* Species: truncatus

Habitat and Distribution:

Bottlenose dolphins inhabit temperate and tropical waters all over the world. It is found in the U.S. from New England down to Florida and west to California. There are also bottlenose dolphins in the United Kingdom and parts of South America, Japan and South Africa.

Those who live in or visit the southern U.S. and Gulf coast have likely been delighted by sightings of coastal bottlenose dolphins from the beach or along local waterways.

There appear to be two types of bottlenose dolphins, 'coastal' dolphins that inhabit nearshore areas, harbors and estuaries, and 'offshore' dolphins, which tend to gather in larger pods out in the pelagic ocean. In fact, some distinguish these two types of dolphins as different species.
Bottlenose dolphins eat fish, squid and crustaceans and have a variety of ways to get their food. Some capture food individually, and some work cooperatively by feeding on fish at mud banks. A group of dolphins chase the fish, creating a wave that carries the fish up onto a mudbank, where the dolphins snap them up. Like other toothed whales, they can find prey using echolocation.
Bottlenose dolphins are sexually mature between 5-14 years of age. Mating and calving takes place throughout the year, and one calf is born after a 12-month gestation period. The calves nurse for about 18 months but may stay with their mother for as long as 6 years.

Bottlenose dolphins were first captured for display in 1913 and since then, they have pervaded marine parks, television and movies. The most popular dolphin was "Flipper," who starred in its own TV show and movie. The original Flipper was named Mitzi, and she lived a short 14 years. The normal lifespan of bottlenose dolphins is at least 40-50 years.

Bottlenose dolphins are listed under the IUCN Redlist as a species of least concern. In the U.S., they are common. NOAA notes that there are 11 stocks of bottlenose in the U.S., some (the western North Atlantic offshore population) numbering over 80,000 individuals.
Bottlenose Dolphin Research:

Because they are so prevalent in marine parks, and many live close to shore, the bottlenose dolphin is one of the most well-studied dolphin species.

In the wild, bottlenose dolphins can be identified using their natural characteristics, including the shape of their dorsal fins. Cataloging individuals allows researchers to learn about the life history of individual whales and the species as a whole.
Pink Dolphins

Are Pink Dolphins Really Smart?

Are Pink Dolphins Really Smart?

Pink Dolphin Intelligence

Most scientists to-date have refused to take a firm stand on the intelligence level of the dolphin, and although many will admit that pink dolphins seem to be intelligent creatures, it is not a proven fact. Darwin's theory bases intelligence on the ability of a species to recognize what it needs to survive, while other schools of thought believe the the size and architecture of the brain, the ability to communicate, or the ability to exhibit playfulness are the indicators.

Another reason that the research on pink dolphin intelligence is limited is because it's difficult and expensive to do in the wild. Dolphins in captivity, may respond differently based on their surroundings and are therefore may not be representative of the wild dolphin. While the U.S. Navy has carried out extensive research on the dolphin and have even trained them to search and even tag mines, that information has not been released to the public.

While most of us outside the scientific realm know that dolphins do communicate with each other and they're one of the most playful animals in the universe, we've never been exposed to the intricacies of the dolphin's brain. Consequently, you may surprised to know that the dolphin brain is actually much larger than the human brain. Dolphins have two hemispheres just like humans however, theirs are split into four lobes instead of three. The fourth lobe in the dolphin's brain actually hosts all of the senses, whereas in a human, the senses are split. When studying the neo-cortex, which is the outside surface of the brain that is responsible for forming perceptions, memories and thoughts, dolphins have more convolution than the most intelligent humans. It is thought that dolphins may also be able to use the hemispheres of their brain separately as they have separate blood supplies which is something that is exclusive only to the dolphin. To add more weight to this supposition, pink dolphins are also able to move their eyes independently which has lead some researchers to suggest that the dolphin may actually be able to sleep with one side of it's brain at a time.

Some researchers have suggested that the size and complexity of the brain at birth is a better measure of intelligence. If that research holds up, however, once more the dolphin comes out on top. The bottle-nose dolphin has a brain mass at birth that is 42.5% of that of an adult humans brain mass. Humans at birth have 25% of their adult counterparts. At 18 months, the brain mass of the bottle-nose dolphin is 80% of the adult human, who doesn't usually achieve this level until the age of three or four.