Different killer whale populations can be distinguished by the kinds of underwater communication sounds they produce.
Killer whales produce a wide variety of acoustic signals that serve various purposes.
Rapid series of clicks are used as echolocation or sonar signals for navigation and detection of objects.
Other kind of sounds, mostly whistles and burst-pulsed signals that resemble squeals, squawks, and screams, are used for social communication within and between groups.
A large proportion of the social sounds of killer whales are quite stereotyped and distinctive in structure.
Each group of whales produces a specific number and type of these discrete calls, which together form its dialect.
Each pod of resident killerwhales has a unique dialect.
Within the resident population, pods with related dialects belong to a clan. Each clan is most likely a continuous lineage that has descended from a common ancestral pod, and their common dialect drifted apart.
Pods with very similar dialects probably split in the recent past, while others with fewer similarities likely have mor distant relationships.
Most calls produced by resident pods can be classified by ear or with the aid of a sound spectrum analyzer into a number of distinctive categories, or types of discrete calls. Each resident pod has a repertoire of about a dozen different discrete call types, although some have as few as 7 and others have as many as 17 types.
Each whale seems to share the entire call repetoire of its pod.
These calls appear to serve generally as contact signals, coordinating group behaviour and keeping pod members in touch when they are out of sight of each other.
The call repetoire of each resident pod has unique features that allow the group to be identified acoustically.
In the side bar of this page you find the catalogue of discrete calls of the Northern Residents Killer Whale population by different call type and the calls made by the different pods.
