Percussive Behavior in the Southern Resident Killer Whale (Orcinus orca) Population at Lime Kiln Point State Park

• Main Author: Jensen, Rylee
• Format: Text
• Language: unknown
• Published: DigitalCommons@USU 2018
• Subjects: Pacific; San Juan; Killer Whale; Orca; Orcinus orca; Killer whale
• Online Access: https://digitalcommons.usu.edu/researchweek/ResearchWeek2018/All2018/10; https://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=1597&context=researchweek

The endangered Southern Resident killer whale (Orcinus orca) is an iconic species in the Pacific Northwest, particularly around the San Juan Islands of Washington state. The population is made up of three pods (J, K, and L) and each individual is given an alpha-numeric identification to designate them to their birth pod and rank (i.e. L87). Although this population has been intensely studied for over 40 years, there is no definitive answer biologists can give as to why killer whales perform above-surface, “percussive” behaviors such as breaching, cartwheeling, pec slapping, and tail lobbing. This study evaluates preferences for these behaviors within this population during the 2016 field season. Our main objectives include examining the type and frequency of percussives across these age and sex classes, comparing trends in these behaviors using existing data from the past 25 years, and reviewing literature to elucidate why these trends may be occurring. Data collection took place from 20 May to 10 August 2016 between 0900 and 1700 each day when the whales were present within the study area. Over the course of the summer, 24 encounters involving percussive behavior were observed. Initial results indicated that adult females performed the most percussives, tail slaps were the most common behavior performed, and that J pod was the most “active” pod. These findings may provide an insight into how percussive behaviors may be indicators for overall behavior (i.e. foraging/travel patterns, disturbance) of this population, which may be important for their conservation.