[MARMAM] New publication: A description of echolocation clicks recorded in the presence of True's beaked whale (Mesoplodon mirus)
Dear MARMAM, On behalf of my co-authors, I am pleased to announce the publication of our article in *The Journal of the Acoustical Society of America*: A description of echolocation clicks recorded in the presence of True's beaked whale (*Mesoplodon mirus*) Annamaria Izzi DeAngelis, Joy E. Stanistreet, Simone Baumann-Pickering, and Danielle M. Cholewiak Abstract True’s beaked whales (*Mesoplodon mirus*) were encountered on two separate shipboard surveys on 24 July 2016 and 16 September 2017 in the western North Atlantic Ocean. Recordings were made using a hydrophone array towed 300 m behind the ship. In 2016, three different groups were sighted within 1500 m of the ship; clicks were recorded for 26 min. In 2017, a single group of five whales was tracked over the course of five hours in which the ship maintained a distance <4000 m from the group. A total of 2938 frequency-modulated (FM) clicks and 7 buzzes were recorded from both encounters. Plausible inter-click-intervals (ICIs) were calculated from 2763 clicks, and frequency and duration measurements were calculated from 2150 good quality FM clicks. The median peak frequencies were 43.1 kHz (2016, n= 718) and 43.5 kHz (2017, n= 1432). Median ICIs were 0.17 s (2016) and 0.19 s (2017). The spectra and measurements of the recorded clicks closely resemble Gervais’ beaked whale clicks (*Mesoplodon europaeus*) and distinguishing between the two species in acoustic data sets proves difficult. The acoustic behavior of True’s beaked whales was previously unknown; this study provides a description of echolocation clicks produced by this species. For the full article, please visit https://doi.org/10.1121/1.5067379 To request a PDF copy, please email annamaria.deange...@noaa.gov. Cheers, Annamaria Annamaria DeAngelis *Research Analyst* Passive Acoustics Research Group | Northeast Fisheries Science Center 166 Water Street, Woods Hole, MA 02543 annamaria.deange...@noaa.gov ___ MARMAM mailing list MARMAM@lists.uvic.ca https://lists.uvic.ca/mailman/listinfo/marmam
[MARMAM] New publication: Using multipath reflections to obtain dive depths of beaked whales from a towed hydrophone array
Dear MARMAM, On behalf of my co-authors, I would like to announce the publication of our article: DeAngelis, A. I., Valtierra, R., Van Parijs, S. M., & Cholewiak, D. 2017. Using multipath reflections to obtain dive depths of beaked whales from a towed hydrophone array. The Journal of the Acoustical Society of America 142(2): 1078-1087 doi:10.1121/1.4998709. Abstract Beaked whales are deep divers, emitting echolocation clicks while at depth. Little is known about the dive behavior of most species; however, passive acoustic data collected with towed hydrophone arrays can provide depth information using multipath reflections of clicks coupled with a two-dimensional localization of the individual. Data were collected during a shipboard survey in the western North Atlantic Ocean using a towed linear hydrophone array. Beaked whale tracks were classified as either Cuvier’s (Ziphius cavirostris) or Gervais’/True’s (Mesoplodon europaeus/Mesoplodon mirus). Weighted species average depths and weighted species standard deviations were 1158 m *+* 287 m for Cuvier’s (n= 24), and 870 m *+* 151 m for Gervais’/True’s (n= 15). Depth uncertainties ranged from 3% to 142% of the average depth. Slant ranges were corrected for depth to provide average horizontal perpendicular distance estimates. The average horizontal perpendicular distance distribution exhibited fewer detections in the first bin than the second. This is the first report of dive depths for Gervais’/True’s beaked whales and use of this method to obtain depths for beaked whales using a towed linear array. For the full article, please visit the publisher's website http://asa.scitation.org/doi/full/10.1121/1.4998709. To request a PDF copy, please email annamaria.i...@noaa.gov. Cheers, Annamaria Annamaria Izzi DeAngelis *Research Analyst* Passive Acoustics Research Group | Northeast Fisheries Science Center 166 Water Street, Woods Hole, MA 02543 ___ MARMAM mailing list MARMAM@lists.uvic.ca https://lists.uvic.ca/mailman/listinfo/marmam
