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sequence involving a big brown bat and a flying insect by ABTC member Cynthia Moss and Kaushik Ghose of the University of Maryland won first prize in the 2004 National Science Foundation Science Visualization Challenge for Multimedia (http:// www.bsos.umd.edu/psyc/batlab). These animations effectively show how the bat keeps its sonar beam centered onto the insect throughout the pursuit sequence. They further indicate that changes in the bat’s beam-forming pat- tern may serve as an index of the switch from search to approach to terminal phase, and thus as an indicator of selec- tive attention.
Donald R. Griffin died on November 7, 2003, leaving an enormous void in the world of animal bioacoustics. Up until a few weeks before his death, he was out in the field with collaborators Gregory Auger, an accomplished video- grapher and photographer, and ABTC members Seth Horowitz and James Simmons, deciphering new clues about the bat’s acoustically-mediated hunting
“Advances in stroboscopic photography, video recording at low light levels, and infrared video recording have opened new windows onto the acoustic behavior of bats.”
behavior. Using a combination of night vision devices and infrared cameras, the team discovered that the rapid burst of sonar broadcasts accompanying suc- cessful captures (the feeding buzz) is more variable in length and in intensity than had been evident from laboratory recordings. Moreover, infrared photog- raphy showed that bats were flying and echolocating in dense swarms, raising new questions about their group behav- ior and ability to avoid jamming each other. Video footage of Don Griffin and the teams of which he was part was fea-
tured in the television program Superbat (Gedeon Programmes, Paris France), broadcast in 2004 in Europe on both French and British television. The pro- gram will be aired in the U.S. later this year on the National Geographic International Channel. Superbat won the World Gold Medal for science docu- mentary in the New York Festivals’ 2005 International Film and Video Competition.
Please visit the ABTC website at: http://cetus.pmel.noaa.gov/Bioacousti- cs.html.AT
References
1 D. R. Griffin, Listening in the Dark (Yale Univ. Press, New Haven CT, 1958; reprinted by Cornell Univ. Press, Ithaca NY, 1986).
2 J. A. Simmons, M. B. Fenton, and M. J. O'Farrell, “Echolocation and pursuit of prey by bats,” Science 203, 16-21 (1979).
3 H.-U. Schnitzler, C. F. Moss, and A. Denzinger, “From spatial orientation to food acquisition in echolocating bats,” Trends in Ecology and Evolution 18, 386-394 (2003).
4 J. A. Simmons, K. M. Eastman, and S. S. Horowitz, “Versatility of biosonar in the big brown bat, Eptesicus fuscus,” ARLO, 2, 43-48 (2001).
Andrea M. Simmons is the current Chair of the Animal Bioacoustics Technical Committee of the Acoustical Society of America (ASA). She is Professor of Psychology and Neuroscience at Brown University, and a Fellow of ASA. Her research interests are in acoustic communication in anu- ran amphibians, and in the structure and function of the auditory and vestibular systems across metamorphic development.
36 Acoustics Today, October 2005