Keys for the status of killer whales in Eastern Kamchatka, Russia : foraging ecology and acoustic behavior

概要

論文の詳細を見る
The foraging ecology and acoustic behavior of the killer whale (Orcinus orca) was studied in Avacha Gulf, Kamchatka Peninsula in the Russian Far East from 1999 through 2003. Two main forms of foraging behavior were observed: the "carousel" type, when killer whales surround a school of fish and swim into the center one after another, and the "asynchronous diving" type, when a killer whale group forages within a determined area, either in a tight group or in subgroups of 2-5 animals. Killer whale groups contained from 1 to 49 animals (mean=9.56), but the typical group size ranged from 6 to 10 animals. No examples of killer whale aggression or hunting behavior directed toward other marine mammals were witnessed. Kamchatkan killer whale groups proved to be highly vocal, producing calls, whistles, and echolocation sounds in different behavioral contexts. Call type repertoires defined for the seven groups within the study population showed that each of these groups shared at least one call type with another group, which by definition means that all these groups belong to the same acoustic clan and the same population. Killer whales observed during this study represent one population and have biological features (group size, foraging and acoustic behavior) similar to the northeast Pacific resident killer whale populations.
野生生物保護学会の論文