Killer whale discrete pulsed call variation.

Animals can increase and diversify vocal complexity and call content by altering internal features within a call. The Northern Resident orca pods, residing off British Columbia, each have their own dialect of structurally discrete and highly stable pulsed calls. The objective of this study is to determine if there are distinctive internal acoustic features within the defined envelope of a single discrete pulsed call (N04) which could potentially relay the signaler’s behavioral circumstance. Orca discrete pulsed calls are highly complex with varying time‐frequency slopes and multiple sidebands. This analysis began with the parsing of the N04 call into different subtypes based on distinctive changes in time‐frequency slopes found in the call spectrograms. Call subtypes were verified using discriminant analysis, and changes in slope trends (ascending, descending, or constant frequency) at designated locations along the calls were compared. Variations in slopes were found between subtypes predominantly in the...