Killer Whale or Orca      Orcinus orca

These sleek predators are members of the dolphin family of whales.  Orcas are less than 30 ft in length and can weigh up to eleven tons.  They are highly social, forming groups made of mature females and their young.  They are commonly found in cool temperate and polar waters but can be found in all oceans.

Unlike other dolphins and whales, the orca has a tall dorsal fin.  In the photograph the male, swimming ahead of the female, has a much taller dorsal fin (up to 6 ft tall).  However the female has a longer life span ( up to 70 years) than a male (up to 60 years).

There are two main branches of whales:  toothed whales that include dolphins, sperm whales and Beaked whales; baleen whales such as the Gray whale or Humpback whale. 

There are three types of local Orcas that appear to be genetically distinct:

    A Resident population that remains within the greater Washington and British Columbia area inland waters.  They feed mainly on fish and sometimes squid.  Individuals have been identified using photos of body shape and color.  This has allowed detailed study of the resident population biology. They have a wide variety of underwater calls.

    A Transient group that moves through the inland waters but also moves off shore, traveling up and down the pacific coast.  They feed on marine mammals.  They have fewer vocalizations than the resident group. 

    An Offshore group found only off the coast.  They feed on schooling fish and possibly on marine mammals and sharks.  They are similar in behavior to the transient group.

The individuals in the photograph (taken off San Juan Island in 1963) are probably members of the resident population.