White-sided Dolphin

(Lagenorhynchus obliquidens)
White-sided Dolphin Santa Barbara Channel
White-sided Dolphin - Photo Credit: Bob Perry

The Pacific white-sided dolphin is a common sighting on our whale and dolphin watching cruises. These dolphins are found within the waters of the Pacific Ocean, and they are regularly found in southern California, especially in winter. During the summer months, they often migrate a bit further north to areas of Oregon and Washington.

They tend to prefer deep waters throughout the year, but Pacific white-sided dolphins regularly come up to investigate boats. This fact tends to complicate matters when researchers are trying to do population counts!

The Pacific white-sided dolphins have three main colors, which help to identify the species when out on our cruises. The belly, as well as the throat and chin, are a creamy white in color, while the dorsal fin, back, and flippers are a dark grey. They also tend to have light gray patches that run along their sides and below their dorsal fins.

Males tend to be a bit bigger than females of the Pacific white-sided dolphin species. Males may get to be a little over 8 feet long, while females tend to top out at 7.5 feet long. This dolphin species is rather active and may interact and co-mingle with other cetaceans in the North Pacific Ocean.

Pacific white-sided dolphins feed on a variety of seafood, including squid, herring, salmon, and anchovies. They will often hunt in groups, and you may see large groups that contain around 90 individual dolphins, although sometimes so-called "super-groups" occur, which may have more than 300 dolphins in them.

These dolphins tend to be very social and take care of each other. They have been studied and communicate differently than some other dolphin species, such as bottlenose dolphins. They also have different echolocation patterns based upon where the live. Near Baja California, they tend to be more active during the day, while elsewhere in the Pacific United States, they appear to be more active at night when observed.