Antarctic beaked whale echolocation signals near South Scotia Ridge

Notes MARINE MAMMAL SCIENCE, **(*): ***–*** (*** 2015) © 2015 Society for Marine Mammalogy DOI: 10.1111/mms.12216 Antarctic beaked whale echolocation signals near South Scotia Ridge J ENNIFER S. T RICKEY , 1 S IMONE B AUMANN -P ICKERING , and J OHN A. H ILDEBRAND , Scripps Institution of Oceanography, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093-0205, U.S.A.; M ARIA V ANESA R EYES R EYES and M ARIANA , Fundacion Cethus, Monteverde 3695 (B1636AEM), Olivos, Provincia de Buenos M ELC ON Aires, Argentina; M IGUEL I N ~ IGUEZ , Fundaci on Cethus, Monteverde 3695 (B1636AEM), Olivos, Provincia de Buenos Aires, Argentina and Whale and Dolphin Conservation, Cap. Bermudez 1598 (B1636EMB), Olivos, Provincia de Buenos Aires, Argentina. Although beaked whales comprise the second-largest family of cetaceans, they are one of the most poorly known groups of all large mammals (Barlow et al. 2006, Jef- ferson et al. 2008). Visual sightings and species identification of beaked whales can be extremely difficult due to their highly elusive behavior and prolonged, deep forag- ing dives with short surface intervals (Tyack et al. 2006). However, beaked whales are the only cetaceans known to use frequency modulated (FM) upsweep pulses to echolocate, and these signals appear to be species-specific in their spectral and tempo- ral characteristics (e.g., Gillespie et al. 2009; McDonald et al. 2009; Baumann-Picker- ing et al. 2010; Rankin et al. 2011; Baumann-Pickering et al. 2013a, b, c). As a result, passive acoustic monitoring is a highly useful technique to investigate the behavioral ecology of these cryptic cetaceans, particularly in remote areas and over long periods of time (Baumann-Pickering et al. 2014). At least five species of beaked whales are known to occur in the Southern Ocean waters south of South America, including Arnoux’s beaked whales (Berardius arnuxii), Cuvier’s beaked whales (Ziphius cavirostris), Gray’s beaked whales (Mesoplodon grayi), southern bottlenose whales (Hyperoodon planifrons), and strap-toothed whales (Mesopl- odon layardii) (MacLeod et al. 2006). Of these five species, an acoustic description has only been made for the FM pulses produced by Cuvier’s beaked whales (Zimmer et al. 2005). Arnoux’s beaked whales appear to have similar frequency characteristics (Rog- ers and Brown 1999) to its sister species in the Northern Hemisphere, Baird’s beaked whale (Berardius bairdii) (Baumann-Pickering et al. 2013b), but a full description of its FM pulse cannot be made from the existing band-limited recordings. Due to the Corresponding author (e-mail: trickeyj@gmail.com).