Analysis of the Acoustic Signals from Three Pygmy Sperm Whales (Kogia breviceps)

• Main Author: Scharnitz, Jennifer
• Format: Other/Unknown Material
• Language: unknown
• Published: NSUWorks 2008
• Subjects: Marine Biology; Oceanography and Atmospheric Sciences and Meteorology; Physeter macrocephalus; Sperm whale
• Online Access: https://nsuworks.nova.edu/occ_stuetd/240; https://nsuworks.nova.edu/cgi/viewcontent.cgi?article=1156&context=occ_stuetd

The pygmy sperm whale, Kogia breviceps, is a small odontocete whose biology and ecology are poorly understood. The Kogiids are taxonomically classified within the Superfamily Physeteroidea due to the presence of a spermaceti organ. This organ, along with the museau de singe/dorsal bursae complex, has been identified as the site of acoustic signal generation for the superfamily. The acoustic signals of this species have been rarely analyzed. Free ranging Kogiids are difficult to locate and stranded animals rarely survive long enough for any significant studies to be undertaken. This study utilized three live-stranded male animals, two adults and one neonate, to further analyze the acoustic repertoire of Kogia breviceps. Only one type of acoustic signal was identified in this study, pulsed signals, which occurred singly and in pulse trains. Two of the animals produced short, low-frequency pulses while the third animal produced short, high-frequency pulses. The measured differences in frequency were determined to be due primarily to the sensitivity of the recording equipment as many of the pulses exceeded the maximum frequency sensitivity of the recording equipment. The calf emitted significantly more pulses than either of the adult animals. Pulses from one adult and the calf were emitted in pulse trains determined to be both passive and active echolocation pulse trains. The pulse trains emitted by the adult animals contained a maximum of 19 pulses per train while the pulse trains emitted by the calf contained a maximum of 197 pulses per train. The pulse length of the calf and the young adult was found to be similar while the interpulse intervals were more similar for the two older animals. Overall, the pulses were found to be dissimilar to those produced by the sperm whale, Physeter macrocephalus.