Pacific White-Sided Dolphin
The Pacific white-sided dolphin is found mainly in deep coastal waters, rarely straying more than 160 km (100 miles) from land. It ranges around the northern Pacific Rim, where a narrow continental shelf and steep continental slope create the deep water conditions preferred by this species. The Pacific white-sided dolphin is found from the waters around Hokkaido, the northern island of Japan, and along the Kuril and Aleutian islands to Alaska. It also occurs along the North American west coast as far south as Baja California, Mexico. This friendly, inquisitive species will ride the bow and stern waves of boats, and investigate motionless vessels.
The Pacific white-sided dolphin have a torpedo-shaped body that allows them to cut through water easily. The body has distinct counter-shading, with black on the upper surface and white below. When swimming with their dorsal fin breaking the water's surface, they look like sharks.
Pacific white-sided dolphins live in small family groups, or pods, of 10 - 20 individuals. A pod contains a single dominant male who mates with the mature females in the pod. Other males in the pod are unlikely to mate. Several pods often group together, and dolphins probably move between pods during these congregations. Pod members hunt for fish together, with each adult consuming about 9 kg (20 lb) of fish per day. In British Columbia, pods have been observed seeking out and harassing orcas that feed on local fish shoals.
Distribution: Continental waters of northern Pacific Ocean; in North America, from the Aleutians Islands and Alaska south to Baja California, Mexico.
Habitat: Deep offshore water.
Food: Fish, squid and octopus.
Size: 1.5 - 3.1 m (5 - 10 ft); 82 - 124 kg (181 - 273 lb).
Maturity: 6 - 8 years
Breeding: Single young born in late summer; gestation is 10 - 12 months.
Life span: 35 years.