Blue Whale
Balaenoptera musculus
Blue Whale
Behaviour
Blue Whale
Feeding
Behaviour
The blue whale eats mostly on
euphasiids or ‘krill’ during the
summer feeding season and lives off stored fat for the
remaining eight months of the year. Blue whales make shallow
dives that last for 10 to 20 minutes while feeding on krill
near the surface. Deep dives are preceded by headstands that
reveal wide tail flukes. Returning to the surface, the whale
exhales blows that rise about 10 meters in the air. Blue
whales eat over five tonnes of food each day during the summer
feeding season. During the other 8 months of the year, it
apparently doesn't eat anything, living off of stored fat. The
blue whale gulps in large quantities of krill and seawater and
then uses it tongue to forces the water out through the baleen
plates.
Blue Whale
Breeding
Ecology
Females reach sexual maturity after about five
years and males just before five years ( ). Gestation requires
ten to eleven months and calves are born late in autumn and
winter. Twins are rare; most females give birth to a single
calf every two or three years. Calves are 6-7 meters long at
birth and they add 90 kilograms each day on average. Calves
are weaned after six or seven months of care. Blue whales can
live to be 90 years old. The relatively small testes suggests
that sperm competition is rare in blue whales. (Species in
which females mate with multiple males have relatively larger
testes to store large quantities of sperm. The sperm of the
numerous males compete to fertilize the eggs).
Blue Whale
Vocalizations
The blue whale has a very deep loud voice of 14
Hz and exceeding 180 decibels. The vocalizations can travel
thousands of kilometers in water suggesting that they might be
able to communicate across vast areas of the oceans. The
sounds have been described as grunts, hums, moans, and clicks
(Wilson and Ruff 1999, Burnie and Wilson 2001).
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