Because dolphins are highly social and vocalize among themselves with a wide range of
sounds, it has been conjectured that they might possess and almost human like intelligence. In the 1950s and '60s the American
neurologist John Lilly conducted well publicized experiments based on this
concept, in which he attempted to communicate with dolphins in their own "language," but other scientists have rejected his
work as poorly documented and lacking scientific validity.
Because of the ability of dolphins to learn and perform complex tasks in captivity, their
continuous communications with one another, and their ability, through training, to approximate the sounds of a few human
words, some investigators have suggested that the animals might be capable of learning a true language and communicating with
Most researchers agree that dolphins exhibit a level of intelligence greater then that
of dogs and even comparable to that of some primates--but not human beings. Research into dolphin intelligence continues at
centers such as Hawaii's Kewalo Basin Marine Mammal Laboratory (The Dolphin Institute).
Dolphins can be found in virtually all the seas and oceans of the world. Some species
are sharply restricted, but many, like the common dolphin , Delphinus delphis,
or the bottle nose dolphin, are found worldwide. Several species are found in fresh water, notably
the Ganges River dolphin, Platanista gangetica; the rivers of South America are the home of the long-snouted dolphin, Inia
geoffrensis, and the small, graceful Sotalia fluviatilis, occasionally seen as far as 1,553 miles up the Amazon River.
Dolphins are quite abundant in some areas of the world. Off the coast of Japan, for example,
populations of the white-sided dolphin, are estimated at 30,000 to 50,000 individuals.
In many species, schools of up to 1,000 travel together, while some species, such as the bottle-nose dolphin, tend to be found
in smaller groups of less than 100. There are 32 species of oceanic dolphins (Delphinidae
family) and six porpoise species (Phocoenidae family). There are five river dolphin species found in five different rivers.
Dolphins and Humans
Dolphins adapt well to human companionship and are readily trained. Bottle-nose dolphins
have become well known performers in may aquariums; they are capable of spectacular tricks and may mimic the sounds of a few
human words. Dolphin species vary in their degree of curiosity and
interaction with humans. Individual dolphins vary to the same degree. Some species are very shy, others will approach humans
with great curiosity. If dolphins have spent time in captivity, they can become very used to people touching them, riding
along side of them, etc., but they also can become mildly aggressive; nipping, pushing, etc.
We all heard of the famous stories about dolphin rescues where a human
is pushed to the safety of the shore by dolphins. Bottle-nose dolphins seem to enjoy pushing items. (Of course we wouldn't
hear about the people being pushed out to sea!)
Traveling as much as they do, dolphins must rest some time. They don't sleep, though. They merely
take cat naps at the ocean's surface for two or three minutes at a time. At night, those naps increase to seven or eight minutes
Dolphins typically cruise at 5 to 7 miles per hour, but they have been clocked at 18 to 22 miles
per hour with top speeds of 30 miles per hour
Dolphins travel in pods of up to 15. A pod typically consists of several adult females, calves
and adult males. Pods may travel together in herds of several hundred individuals. Dominance or aggression, in the form of
a showing of teeth, tail smacking, jaw snapping or head butting, establishes the hierarchy in the pod.