In the marine environment, Orcas
rely on complex communication in order to navigate,
forage, locate each other, and express their moods. The
most notable form of communication is vocal. Orca
vocalizations have now been well-documented by
researchers who use hydrophones to record their sounds.
These sounds consist of whistles, buzzing sounds, and
screeches. Among Resident Orcas near BC, each pod has
its own style of calls, or dialect, and this is thought
to help maintain group cohesion.
Like many other odontocetes, Orcas
are also equipped with echolocation. In dark waters
where visibility is low, echolocation aids in finding
food and in navigation. Echolocation consists of a
series of clicks produced inside the head of the whale.
The sharp sounds leave the animal through its forehead,
or melon, and then rapidly travel through the water. The
sounds bounce off any nearby objects or obstacles and
the echoes return to the whale and are picked up by a
hearing mechanism in its lower jaw. The whale brain is
able to process these returning clicks in a way that
allows the whale to maintain a three dimensional sense
of its surroundings.
Resident fish eating Killer Whales
vocalize loudly and often. But Transient mammal eating
Killer Whales are characteristically much more quiet.
Since their mammalian prey have good hearing in the
range of Killer Whale calls, it is thought that
Transients avoid making calls so as not to alert their
prey to their presence.
Orcas also communicate through
body language. Underwater bubbling, breaching, tail
slapping, body quivering, and head nods are just a few
examples of movements that whales may make to display
aggression, submission, excitement, etc.