Often confused with the Common dolphin and the Dall's Porpoise, the Pacific White Sided dolphin has a stripe or streak of white, or pale grey,  along its flanks and sides, giving it it's common name.    This also gives it a local name of Pacific Striped or White Striped dolphin, not to be confused with the Striped dolphin.    Its belly and undersides of throat and chin are white, while the beak is dark and dark rings encircle the eyes.     The tall and falcate dorsal fin has side patches partially grey in colour, with the lower portion of the melon and face also pale grey.  The upper side of the body is dark grey to black.

This highly outgoing dolphin is found in the deep temperate waters of the northern Pacific, and seen to prefer temperatures between 6 and 17 degrees.

Key Facts of the Pacific White Sided Dolphin:

Adult length:   The average length  is about  1.7 to 2 metres, but can reach up to 2.4 metres.

Adult weight:   Weight is generally around 85 kg to 100 kg, with a maximum of 150 kg.

Lifespan:   This species is known to live as long as 45 years.

Habitat:   The Pacific White Sided dolphin is found in the coastal waters of the north Pacific and the Bering Sea, particularly off California and Japan.  They migrate to the north in the spring and to the south in the fall.   They move away from California in the summer and fall.  Travelling closer to the coast in the spring when the water is warmer.

Group size:   In some waters, family pods can number around 30 individuals.   But often this dolphin is found in groups of several hundred, sometimes even thousand.   Pods can be as be as large as 2.5 km  wide  and 16 km long!

Behaviour:   Highly gregarious, the Pacific White Sided dolphin is very energetic and acrobatic.   They enjoy leaping and bow-riding, and are often unseen when porpoising at high speed, due to their spray.    This species is frequently seen to be in the company of Risso's dolphins and Common dolphins, and sometimes (though not as often) baleen whales.  It is very inquisitive and doesn't fear the approach of humans.

Reproduction:    Mating and births occur during the summer or beginning of autumn (Fall) in the northern hemisphere.  The length of gestation is estimated at 9 to 12 months with an average of 10.

Calves:   The average size for a newborn is 80 to 95cm long.   Males attain sexual maturity when they measure 1.7 to 1.8 metres and females when they reach 1.75 to 1.86 metres.

Diet & Feeding:    Pacific White Sided dolphins feed  on small schooling fish of anchovies, hakes, herrings, sardines, and octopus, consuming approximately 9 kg a day.

Noteable features:   The Pacific White Sided dolphin is a fast and powerful swimmer.  It swims at speeds of 22.2 km per hour and can hold this speed for 10 to 15 minutes.  In order to breathe it surfaces every 15 to 20 seconds.   Generally moving in herds of 20 to 40, though often seen with up to 1,000, these dolphins separate into small groups of the same age and gender to feed.

Threats:   This dolphin is susceptible to being accidentally caught in fishing gear and nets, and are also a popular catch in Japan's coastal harpoon fishery, with thousands being taken throughout the years.    Japan has been known to still hunt this species, though it isn't certain what effects it has had on the status in the surrounding island waters.      This dolphin is also very popular for marine acts in Canada, America and Japan, though only a third of the number taken for this purpose survive their first year of captivity.

Population:   The population of this species in the NorthEastern Pacific is estimated to be between 30,000 and 50,000. 

Other Pacific White Sided Dolphin Facts:

It will frequently swim along with the Atlantic White Sided dolphin

Associating with Risso's dolphins, they also swim with Grey whales, and Humpback whales as well.

Surprisingly, they are nocturnal feeders

They have 21 to 28 small pointed slightly curved teeth, the reason it was given it's scientific name Obliquidens meaning "slanted tooth"

These dolphins are commonly found swimming with the Northern Right Whale dolphin

The Pacific White Sided dolphin has a short thick beak, strongly marked in black and a gleaming white underside.

Most members of the Pacific White Sided dolphin family rest while suspended just below the surface