Dear Colleagues, My coauthors and I are pleased to announce the online publication of our new paper in the Journal of the Acoustical Society of America:
Smith AB, Pacini AF, Nachtigall PE, Laule GE, Aragones LV, Magno C, Suarez LJA (2019) Transmission beam pattern and dynamics of a spinner dolphin (*Stenella longirostris*). J. Acoust. Soc. Am. 145(6). https://doi.org/10.1121/1.5111347 Copies can be obtained at the above link or by contacting me directly. Abstract: Toothed whales possess a sophisticated biosonar system by which ultrasonic clicks are projected in a highly directional transmission beam. Beam directivity is an important biosonar characteristic that reduces acoustic clutter and increases the acoustic detection range. This study measured click characteristics and the transmission beam pattern from a small odontocete, the spinner dolphin (*Stenella longirostis*). A formerly stranded individual was rehabilitated and trained to station underwater in front of a 16-element hydrophone array. On-axis clicks showed a mean duration of 20.1 µs, with mean peak and centroid frequencies of 58 and 64 kHz [standard deviation (s.d.) ±30 and ±12 kHz], respectively. Clicks were projected in an oval, vertically compressed beam, with mean vertical and horizontal beamwidths of 14.5° (s.d. ±3.9) and 16.3° (s.d. ±4.6), respectively. Directivity indices ranged from 14.9 to 27.4 dB, with a mean of 21.7 dB, although this likely represents a broader beam than what is normally produced by wild individuals. A click subset with characteristics more similar to those described for wild individuals exhibited a mean directivity index of 23.3 dB. Although one of the broadest transmission beams described for a dolphin, it is similar to other small bodied odontocetes. Cheers, -- Adam B. Smith, Ph.D. *Guest Investigator * *Sensory Physiology and Sensory Ecology Laboratory* *Woods Hole Oceanographic Institution* *Fulbright U.S. Scholar* *University of Iceland's Research Centre in Husavik* *Fulbright-NSF Arctic Research Initiative*
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