Resident fish-eating killer whales are very vocal. They produce a variety of echolocation or sonar clicks, squeaks, whistles and frequently and exchange calls to maintain contact with each other while traveling and hunting for food.
Resident pods have unique language dialects consisting of a set of 7 to 17 distinct stereotyped calls. Pods with dialects that have calls in common are considered to belong to the same acoustic clan. By this criterion, the Northern Resident killer whale community has three clans (referred to as A, G and R) and the Southern Resident community has a single clan (referred to as J).
All calls for Resident killer whales are labeled alpha-numerically with "S" for southern and "N" for northern. Listen to the S36 call by L pod and then the S6 call of K pod. Source: Dr. Rich Osborne
Call Types of Transient Killer Whales
Transient killer whales tend to produce very few vocalizations while travelling and can often pass by a hydrophone without being detected. Transients are stealth hunters because their prey (i.e. whales, porpoises, sea lions and seals) have excellent hearing and would flee if they heard these predators (transients). However, soon after attacking and consuming prey, they become quite vocal, and can be easily identified by their unique calls.
Transients have a more fluid social structure than residents, therefore have a lack of group-specific dialects. Instead of a wide variety of dialects, most transient calls belong to the same repertoire of 4 to 6 distinct call types. Though there is some variation between the call repertoires of B.C., Alaskan and Californian populations, all transient killer whales along the Pacific Northwest coast appear to share the same dialect. Listen to Pacific coast transient calls. Source: Dr. John Ford
Call Types of Offshore Killer Whales
Little is known about the vocal patterns of offshore killer whales; however, their calls are different from those of either resident or transient killer whales. Whether all offshore killer whales produce the same calls, or if they have distinct dialects remains to be discovered. Similar to residents, they are vocally active, which suggests that they rarely hunt marine mammals. Listen to offshore calls. Source: Dr. John Ford