Lagenorhychus obliquidens
Pacific White-Sided Dolphins are usually 2.1m to 2.4m (7-8ft)
and weigh 90 to 140 kg. These robust animals are mostly black
with a gray and white dazzle pattern, short thick beaks, and
curved dorsal fins. However, they can usually be recognized
from a distance by there playful behaviour. White-sides (or
lags as they are often called) are extremely acrobatic and
social animals. They love to perform somersaults and cart
wheels and even swim along on their backs. They truly appear
to be awaiting applause! In fact, one lag even jumped onto
the deck of a ship, which was 3m (10ft) above the water. This
animal was quickly thrown back into the ocean by the amused
crew! Pacific White Sided dolphins have been observed swimming
and/or feeding in the company of many other marine mammals,
including the Northern Right Whale and Risso's dolphin, just
to name a few.
The Pacific White-Sided Dolphin lives in coastal waters off
the B.C. coast in the Northern Pacific. These lively animals
are generally found in large herds, sometimes as big as several
thousand individual animals. These herds are generally the
largest in September and October, averaging about 115 individuals,
whereas in the winter months the herds are usually only 35
members large (though this is still a large group). Herd size
peaks in the fall because this time of year is breeding season
for these animals. Once they reach a length of 1.8m (6 ft)
Pacific White Dolphins begin reproducing and have a gestation
period (pregnancy) of 10-12 months. At birth, these marine
mammals are about 1m (3 ft) in length.
Lags are carnivorous and feed primarily on squid, herring,
sardines, hake, and anchovies. Their primary cause of death
at present is human activity; they often become entangled
in fishing nets which prevents them from coming up for air.
These animals also fall victim to killer whales, and the occasional
shark.
Like all dolphins, Pacific White Sides use sonar (a series
of rapid clicks) for communication and to locate objects,
such as prey and obstacles. Dolphins are thought to be extremely
intelligent, in fact some scientists say they are as intelligent
as humans. However, measuring intelligence is not an easy
task so this is a difficult comparison to make. In fact we
often end up measuring how similar animals are to humans,
rather than their absolute intelligence. The vocabulary of
these animals is incredibly diverse and includes squeaks,
squawks, groans, rattles and clicks. They are also able to
mimic the sounds of other animals, and they can be trained
to perform according to human vocal instruction.
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