Physical Description

  • Small marine mammals, weighing an average of 170 pounds with length just under 6 feet.
  • Rounded forehead and 40-57 pairs of small, sharp teeth in beak.
  • Body is sleek and aerodynamic with a relatively large, triangular dorsal fin on back.
  • Dark gray coloration on back, forming V on sides, with yellowish tan side panels.
  • A narrow dark stripe runs from the lower jaw to the flipper.
  • Males slightly larger than females.

Range

  • Cosmopolitan distribution.
  • Washington down south to coast of Chile in Pacific.
  • East Coast of Canada to Florida in Atlantic.
  • Found in North Pacific north of Hawaii, New Zealand, Tasmania, Southeast Asia.
  • All throughout Europe and North Africa, eastern Africa.

Habitat

  • Prefer warm tropical to cool temperate waters.
  • Primarily found in oceanic and offshore waters.
  • Often in association with underwater ridges, seamounts, and continental shelves where cold, nutrient-dense bottom water is upwelling.

Reproduction

  • Males become sexually mature at 10 and females at 8 years old.
  • Off the California coast, calves are born in winter after a 10-11 month gestation period.
  • In the eastern tropical Pacific, calves are born year-round.
  • Every 2-3 years, an adult female will give birth to a baby that is 2.5 to 3 feet long.
  • Calves nurse for about a year, and are dependent on their mothers for another year or more.

Diet

  • Squid, small schooling fish.
  • They often swim with schools of tuna and flocks of seabirds.

Predators

  • Common dolphins’ natural predators are larger sharks, like bull sharks and great whites.
  • Common dolphins are hunted for meat and oil in Russia, Japan, and countries around the Black Sea and Mediterranean Sea.

Interesting Facts

  • Common dolphins are called common because they are some of the most abundant marine mammals on earth..
  • They are sometimes found swimming in pods of over 3000 individuals..
  • They are very active at the surface, somersaulting and leaping out of the water..

Sources: Voices in the Sea; NOAA Fisheries; Dive-The-World.com

Photo: Thomas A. Blackman

To hear a common dolphin’s call and see videos of them swimming, visit Voices in the Sea, a collaboration between the Pacific Life Foundation and Scripps Institution of Oceanography.