Abstract
During foraging dives, sperm whales (Physeter macrocephalus) produce long series of regular clicks at 0.5-2 s intervals interspersed with rapid-click buzzes called "creaks". Sound, depth and orientation recording Dtags were attached to 23 whales in the Ligurian Sea and Gulf of Mexico to test whether the behaviour of diving sperm whales supports the hypothesis that creaks are produced during prey capture. Sperm whales spent most of their bottom time within one or two depth bands, apparently feeding in vertically stratified prey layers. Creak rates were highest during the bottom phase: 99.8% of creaks were produced in the deepest 50% of dives, 57% in the deepest 15% of dives. Whales swam actively during the bottom phase, producing a mean of 12.5 depth inflections per dive. A mean of 32% of creaks produced during the bottom phase occurred within 10 s of an inflection (13x more than chance). Sperm whales actively altered their body orientation throughout the bottom phase with significantly increased rates of change during creaks, reflecting increased manoeuvring. Sperm whales increased their bottom foraging time when creak rates were higher. These results all strongly support the hypothesis that creaks are an echolocation signal adapted for foraging, analogous to terminal buzzes in taxonomically diverse echolocating species.
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Selected References
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- Charnov E. L. Optimal foraging, the marginal value theorem. Theor Popul Biol. 1976 Apr;9(2):129–136. doi: 10.1016/0040-5809(76)90040-x. [DOI] [PubMed] [Google Scholar]
- Clarke M. R. Function of the spermaceti organ of the sperm whale. Nature. 1970 Nov 28;228(5274):873–874. doi: 10.1038/228873a0. [DOI] [PubMed] [Google Scholar]
- Goold J. C., Jones S. E. Time and frequency domain characteristics of sperm whale clicks. J Acoust Soc Am. 1995 Sep;98(3):1279–1291. doi: 10.1121/1.413465. [DOI] [PubMed] [Google Scholar]
- Jaquet N., Dawson S., Douglas L. Vocal behavior of male sperm whales: why do they click? J Acoust Soc Am. 2001 May;109(5 Pt 1):2254–2259. doi: 10.1121/1.1360718. [DOI] [PubMed] [Google Scholar]
- Kooyman G. L., Ponganis P. J. The physiological basis of diving to depth: birds and mammals. Annu Rev Physiol. 1998;60:19–32. doi: 10.1146/annurev.physiol.60.1.19. [DOI] [PubMed] [Google Scholar]
- Madsen P. T., Payne R., Kristiansen N. U., Wahlberg M., Kerr I., Møhl B. Sperm whale sound production studied with ultrasound time/depth-recording tags. J Exp Biol. 2002 Jul;205(Pt 13):1899–1906. doi: 10.1242/jeb.205.13.1899. [DOI] [PubMed] [Google Scholar]
- Miller Patrick J. O., Johnson Mark P., Tyack Peter L., Terray Eugene A. Swimming gaits, passive drag and buoyancy of diving sperm whales Physeter macrocephalus. J Exp Biol. 2004 May;207(Pt 11):1953–1967. doi: 10.1242/jeb.00993. [DOI] [PubMed] [Google Scholar]
- Møhl B., Wahlberg M., Madsen P. T., Miller L. A., Surlykke A. Sperm whale clicks: directionality and source level revisited. J Acoust Soc Am. 2000 Jan;107(1):638–648. doi: 10.1121/1.428329. [DOI] [PubMed] [Google Scholar]
- Møhl Bertel, Wahlberg Magnus, Madsen Peter T., Heerfordt Anders, Lund Anders. The monopulsed nature of sperm whale clicks. J Acoust Soc Am. 2003 Aug;114(2):1143–1154. doi: 10.1121/1.1586258. [DOI] [PubMed] [Google Scholar]
- Shapiro E. T., Tillil H., Rubenstein A. H., Polonsky K. S. Peripheral insulin parallels changes in insulin secretion more closely than C-peptide after bolus intravenous glucose administration. J Clin Endocrinol Metab. 1988 Nov;67(5):1094–1099. doi: 10.1210/jcem-67-5-1094. [DOI] [PubMed] [Google Scholar]
- Thode Aaron, Mellinger David K., Stienessen Sarah, Martinez Anthony, Mullin Keith. Depth-dependent acoustic features of diving sperm whales (Physeter macrocephalus) in the Gulf of Mexico. J Acoust Soc Am. 2002 Jul;112(1):308–321. doi: 10.1121/1.1482077. [DOI] [PubMed] [Google Scholar]
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