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NAME: DOLPHIN
SCIENTIFIC
NAME: PHYLUM: CHORDATA; CLASS: MAMMALIA;
ORDER: CETACEA; SUBORDER: ODONTOCETI; FAMILY: DELPHINIDAE & PLATANISTOIDEA
LOCATION: ALL THE WATERS OF THE WORLD.
RECOGNITION
FEATURES: RANGING IN SIZE FROM 1.2-9.5
METERS, DOLPHINS ARE KNOWN FOR THEIR SLEEK BODY, AND ELONGATED SNOUT FILLED
WITH TEETH. DOLPHINS RANGE IN COLOR, AS
WELL AS SIZE, AND CAN BE FOUND IN PINK, GREY, WHITE, AND THE BLACK AND WHITE
ORCAS. THE MOUTHS OF MANY
DOLPHINS—ESPECIALLY THE WELL-KNOWN, BOTTLENOSE—IS SHAPED INTO A KIND OF
PERMANENT GRIN, WHICH ADDS TO THE IDEA OF DOLPHINS AS FRIENDLY ANIMALS.
DETAILS:
Dolphins still have
a place in the hearts of people across the world, and for good reason. Dolphins are generally thought to be among
the most intelligent animals on the planet, and have a very large,
well-developed brain, roughly the same size as a human brain, and many
scientists feel that the possibility exists that dolphins are roughly as
intelligent as humans. Studies of the
cerebral cortex—the part of the brain used for reasoning and thinking—have
found it also to be similar to human’s brains.
Dolphins have been observed using tools—breaking off sponges to guard
their nose while scavenging—and also teaching their young this technique. While studies have yet to prove conclusively
the level of dolphin intelligence, their behavior and level of socialization is
not up for debate.
Dolphins generally
live in small groups of around 12 members, called pods or schools, and have a
developed language consisting of a series of clicks, whistles, and other sounds,
known as echolocation. The clicks that
are used, many as quickly as 800/second, are used for communication and as
sonar, to help them keep direction and located food and other objects. The sound waves bounce off the object and
upon return, are absorbed by the dolphin’s thick lower jaw, then transmitted to
the inner ear, and finally, the brain.
Dolphin pods are
highly developed social structures with members taking care of their sick, old,
and injured, and the bonding between members can become quite strong. Members of the pod also work together in
instances of hunting. Dolphins have been
observed “corralling” schools of fish, as one or two members of the pod circles
around, driving the fish into a tight group, while the other members take turns
charging into the mass. In addition to
helping members of their own pod and species, anecdotes exist of dolphins
protecting humans and other animals from sharks and other predators. The members of pods travel side-by-side in
order to enhance the use of the echolocation.
Pods can differ in their components.
Some, called ‘bachelor pods’, are made up entirely of old and young males,
while a ‘nursery pod’ consists of females and their young. A ‘nuclear pod’ is made up of a female and a
male, and possibly a young dolphin.
Larger pods are typically thoroughly mixed.
Dolphins are
mammals, and are similar to whales and porpoises. These creatures can measure anywhere from 1.2
to 9.5 meters. The largest dolphin is
the misnamed killer whale, or Orca, which lives in waters ranging from the
North Artic to Antarctica. All dolphins are carnivores, living on a
diet, typically of fish and squid.
Orcas, however, have a more diverse diet, consuming medium sized fish such
as tuna, herring, salmon, and Chinook.
Larger Orcas prey on larger animals, consuming sharks (even great
whites), whales, seals, sea lions, and birds.
Orcas are extremely bright hunters, and use many different strategies to
capture their prey. Orcas have been seen
vomiting fish on the surface and then killing the birds that come to eat. Others have been observed working as a team
to create a wave to dislodge a seal from a rock as younger pups wait below.
Dolphins have a
close relationship with man, and aside from the movies and TV shows which
popularized the animals, these creatures have also been used as therapy
treatments for people with psychological and neurological problems. The military also has conducted tests with
dolphins, attempting to teach them to discover undersea mines, and even kill
enemy divers.
Aside from dogs and
cats, the most well-known and liked member of the animal kingdom is perhaps the
dolphin. In recent times, the dolphin
has been immortalized in television shows, such as “Flipper”, and even in
sports teams like the Miami Dolphins, but throughout recorded history, this
intelligent and friendly animal has been mythologized. From the ancient Greeks to the Hindus, images
of dolphins have been found on coins and in their writings, and almost always
were seen as a sign of good fortune.
admin2007-06-20 23:30:10
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