Killer Whale (Orcinus orca) Pulsed Calls in the Eastern Canadian Arctic

Abstract


 Killer whales (Orcinus orca) produce a variety of acoustic signal types used for communication: clicks, whistles, and pulsed calls. Discrete pulsed calls are highly stereotyped, repetitive, and unique to individual pods found around the world. Discriminating amongst pod specific calls can help determine population structure in killer whales and is used to track pod movements around oceans. Killer whale presence in the Canadian Arctic has increased substantially, but we have limited understanding of their ecology, movements, and stock identity. Two autonomous passive acoustic monitoring (PAM) hydrophones were deployed in the waters of Eclipse Sound and Milne Inlet, in northern Baffin Island, Nunavut, Canada, in August and September 2017. Eleven killer whale pulsed call types, three multiphonic and eight monophonic, are proposed and described using manual whistle contour extraction and feature normalization. Automated detection of echolocation clicks between 20 and 48 kHz demonstrated little to no overlap between killer whale calls and echolocation presumed to be narwhal, which suggests that narwhal remain audibly inconspicuous when killer whales are present. Describing the acoustic repertoire of killer whales seasonally present in the Canadian Arctic will aid in understanding their acoustic behaviour, seasonal movements, and ecological impacts. The calls described here provide a basis for future acoustic comparisons across the North Atlantic and aid in characterizing killer whale demographics and ecology, particularly for pods making seasonal incursions into Arctic waters.

Vocal Behaviour of Killer Whales in the Eastern Canadian Arctic and the Role of Calls in Predator-prey Interactions

“…I will focus on pulsed calls, as that is the call type in other regions that shows group-specificity (Ford, 1987(Ford, , 1991Deecke et al, 2010). I will take a set of measurements of the acoustic features of the calls following previously established methods and measurements (Sportelli, 2019;Madrigal et al, 2021;Selbmann et al, 2021) and use a random forest analysis and a principal component analysis to determine whether call types differ among groups, indicating groupspecific dialects.…”

Vowels and Diphthongs in Sperm Whales

“…This is primarily obvious in whistle-like vocalizations of dolphins, orcas, or beluga whales (Filatova et al, 2015;Panova et al, 2016Panova et al, , 2019. Even pulsed call vocalizations seemed to primarily be modulated in the fundamental frequency (F0) (Sportelli, 2019;Wellard et al, 2020). The same is true for vocalizations that Panova et al (2016) call "vowel"-like based on an acoustic impression.…”