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Gray
Whales
The
gray whale family name is Eschrichtius robustus, with a funny scientific
sub-classification; Cetacea Mysticeti, with Mysticeti meaning mustache!
This is because gray whales don't have teeth, but rather baleen that are
fibers inside their mouths used to filter the smallest ocean creatures
out of the water. They have also been known as California Gray Whale,
Devilfish, Mussel-digger, and Scrag Whale. They are a fairly large whale
with many short baleen rows, a narrow head and no dorsal fin Most have
crustaceans growing on their backs. The gray is a mammal like you and
I, it bears its babies live, breathes air, has warm blood, has some hair
and nurses its young. And the gray whale has two blowholes. A female gray
can grow from 35 to 50 feet and weigh as much as 30 - 35 tons while the
male is smaller at 46 feet and 14 tons. The largest gray whale ever recorded
was 51 feet long and weighed 39 tons. They are usually a blotchy gray
with patches of light and darker colors.
The whale
comes to the surface to breath. But it can stay underwater for up to 15
minutes before running
out of air. Air is expelled through the blowholes on the its back, creating
a spout. Grays are curious and often playful in their movements. Breaching
is when the whale leaps almost clear of the water and falls back with
a splash. Sounding is the term for showing it's flukes or tail. Spy hopping
is when the whale propels itself vertically upward out of the water until
it can see and can last from 10 to 30 seconds.
The whale
spends the summer and the early fall months in the arctic waters of the
Chukchi and Bearing Seas feeding off bottom sediment before heading south
to breed and for warmer waters. In the late fall, the whales start their
5000 mile migration south to Baja California, one of the longest trips
for mammals. There are now over 23,000 gray whales passing by the west
coast of the United States in December and January on their southern migration
and going
north in March and April .
The gray's
diet consists of tube worms and sessile polychaetes that live in sediment
on the ocean floor. In the shallower waters, the whale will dive down
for 3 to 5 minutes and bump the bottom, creating clouds of food rich sediment
which it scoops up with it's mouth. It then expels the water through the
baleen in its mouth, leaving behind its dinner, which it promptly swallows!
A trail of dents in the ocean floor is left behind. While migrating the Gray will feed at the surface on small fish and mysids (Acanthomysis sculpta)
amphipods which are tiny shrimp-like creatures.
The female
gray whale usually produce offspring every 2 to 3 years after a gestation
period of 12 to 13 months. Another female gray whale
helps the mother when the calf is born, she's the auntie. The shallow
lagoons of Baja California provide the perfect nursery for the newborn
calf, which weighs about 1,500 pounds and is about 15 feet long. The mother
whale's milk is 53% fat, which is 10 times richer than cow's milk and
necessary for the calf to build up blubber for the long migration north.
They are weaned at about eight months, after the trip back.The calf must
get in shape before the long trip north and swims against the lagoon currents
to develop its swimming muscles. By the time the whales leave the lagoons
the calves are about 19 feet long, and weigh about 3,000 pounds.
The enemies
and hunters of the gray whale include man, sharks, and Orca whales.
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