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Dolphins are warm blooded, breathe air and give birth to
live young.
Their streamlined, hydrodynamically efficient body shape is most suited to a
predatory life at sea.
The Indo-Pacific bottlenose dolphin at Monkey Mia is a member of the toothed
Cetacean family.
Members of this widespread group include other species of dolphins, porpoises,
killer wales and other toothed whale species.
Dolphins have pointed beaks and conical teeth which distinguish them from porpoises
that have spade like teeth and no beaks.
Dolphins sleep and rest in groups.
While a dolphin`sleeps' half the brain remains conscious, opening the blowhole
to breathe and slowly moving from surface to near surface with one eye open
watching for signs of disturbance.
They grow to a maximum length of 2.3m, developing speckling
on the belly as they mature between 7 and 12 years.
A fully-grown bottlenose dolphin weighs about 120 kg, compared
to an average human male weighing 80kg.
Some dolphins live for up to 40 years and more.
The female dolphin swims towards the shore until her belly
is scraping the sea floor - then lunges.
Heaving her body almost entirely out of the water, she seizes
the flapping, gasping mullet.
This moment is dangerous, if she lunge too far she risks
becoming stranded.
Using strong muscular contractions and a wriggling motion
she returns to the water.
Some 50 metres offshore her calf is watching, perhaps memorising
this skill for a time when she is strong enough to join the
fray.
Some Shark Bay dolphins use marine sponges on their rostrum
(beak) as a protective tool when foraging for food on the
seabed.
Seagrass meadows are also feeding grounds for green turtles
and dugongs that eat seagrasses.
The deeper waters around Shark Bay are home to large carnivorous
fish such as tailor as well as manta rays and sharks.
Sharks are a constant threat to dolphins and dugongs, particularly
young, old and sick animals.
In Shark Bay about 1/3 of dolphin calves have shark bite
scars.
Twelve species of shark have been identified in Shark Bay.
The tiger shark is the primary predator of dolphins.
Dolphins travel in groups to better detect sharks, diving
deep and swimming swiftly to avoid them.
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