Habitat and Distribution | Physical Appearance | Behavior | Breeding and Reproduction | Diet | Fun Facts
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Habitat and Distribution
Pacific white-sided dolphins (scientific name: Lagenorhynchus obliquidens)
are found in the Pacific Ocean. They prefer deep offshore waters with temperatures ranging
from 43 to 62°F (6 to 17°C), but generally during the winter months Pacific white-sided
dolphins migrate to inshore waters. Pacific white-sided dolphins range from the Aleutian
Islands through Alaska to the tip of Baja California in the eastern Pacific ocean, and from Japan
to the Kuril Islands in the western Pacific .
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Physical Appearance
Pacific white-sided dolphins have a robust body and are also called "white-striped
dolphins" because of the light stripe present on both sides of their bodies. Their mouths
contain 84 - 130 sharp teeth that are slightly curved.
Color: Pacific white-sided dolphins have a black or gray upper side and
white belly, throat, and chin. The beak is short, thick, and dark. The face is light gray and a
black ring can be seen around the eyes. Patches of gray are found on either side of the dolphin's
body. The underside of the tail is darkly colored and a characteristic gray or white stripe is
present along the flank.
Length and Weight: : Pacific white-sided dolphins are generally
6 - 8 feet (1.8 - 2.4 meters) in length and weigh 185 - 330 pounds (84 - 150 kg).
Fins: The front flippers are black in the front, fading to light gray
at the tip. The dorsal fin, which is tall and curved, has a similar coloring pattern to that of the flippers.
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Behavior
Pacific white-sided dolphins are very social animals and can
often be seen performing somersaults and other playful acrobatics in the ocean. In offshore waters,
they often swim in groups, or pods, of hundreds. Occasionally thousands of these dolphins can be
seen swimming together. Closer to shore, Pacific white-sided dolphin pods consist of about 30
individuals of a basic family unit. This species can often be seen swimming with Risso's dolphins
and common dolphins. Occasionally, Pacific white-sided dolphins will be seen associating with baleen
whales. Like all dolphins, the Pacific white-sided dolphin communicates by means of echolocation.
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Breeding and Reproduction
Female Pacific white-sided dolphins reach sexual maturity around 5 - 6 years of
age and males are sexually mature at 8 - 10 years. Mating occurs in the summer to late fall, and a
female dolphin is pregnant for a period of 10 months. After 10 months, the female gives birth to one
calf every two to three years. A newborn calf is approximately 3 feet (1 meter) long and weighs 30 -
50 pounds (1.6 - 22.7 kg). A baby will drink its mother's milk and stay with her for about a year after it is born.
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Diet
Pacific white-sided dolphins are carnivorous (meat eating) and feed primarily on
squid, herring, sardines, hake, octopus, and anchovies. They consume about 20 pounds (9 kg) of food a
day. When hunting, these dolphins break up into smaller groups of approximately 10 - 20 individuals
to capture their prey.
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Fun Facts
- Pacific white-sided dolphins swim in groups with other dolphins and sea lions.
Often they can be seen doing flips in the air and leaping out of the water!
- These dolphins can live up to 45 years!
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