Are Caribbean reef sharks, Carcharhinus perezi, able to perceive human body orientation?
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The present study examines the potential capability of Caribbean reef sharks to perceive human body orientation, as well as discussing the sharks’ swimming patterns in a person’s vicinity. A standardized video method was used to record the scenario of single SCUBA divers kneeling in the sand and the approach patterns of sharks, combined with a control group of two divers kneeling back-to-back. When approaching a single test-subject, significantly more sharks preferred to swim outside the person’s field of vision. The results suggest that these sharks are able to identify human body orientation, but the mechanisms used and factors affecting nearest distance of approach remain unclear.
KeywordsApproach Humans Swim patterns Sharks
We thank M. Tomasello and A. Miklósi for their suggestions, as well as the two anonymous reviewers for critical reading of the manuscript and editorial suggestions. Furthermore, we also thank the test-subjects for their efforts, which made this project possible.
- Baldridge HD (1988) Shark aggression against man: beginnings of an understanding. Calif Fish Game 74:208–217Google Scholar
- Blair RC, Sawilowsky SS, Higgins JJ (1987) Limitations of the rank transform in factorial ANOVA. In: Balakrishnan N (ed) Communications in statistics: computations and simulations B16. Taylor and Francis, London, pp 1133–1145Google Scholar
- Compagno LJV (1984) Sharks of the world. Part 2: Carcharhiniformes. FAO species catalogueGoogle Scholar
- Conover WJ (1999) Practical nonparameteric statistics, 3rd edn. Wiley, New York, pp 396–406Google Scholar
- Frid A, Dill L (2002) Human-caused disturbance stimuli as a form of predation risk. Conserv Ecol 6, 11. http://www.consecol.org/vol6/iss1/art11. Accessed 2013
- Itakura S, Anderson JR (1996) Learning to use experimenter-given cues during an object-choice task by a capuchin monkey. Curr Psychol Cogn 15:103–112Google Scholar
- Pettigrew JD (1991) Evolution of binocular vision. In: Cronly-Dillon JR, Gregory RL (eds) Vision and visual dysfunction, vol 2., Evolution of the eye and visual sytem. CRC Press, Boca Raton, pp 271–283Google Scholar
- Ritter EK (2006) Understanding sharks. Krieger, MelbourneGoogle Scholar
- Ritter EK (2012) Shark–human interaction. Situations findings recommendations. Shark School Publishing, PensacolaGoogle Scholar
- Ritter E, Lutz K, Levine M (2008) When humans and sharks meet. In: Olsson F (ed) New developments in the psychology of motivation. Nova Biomedical Books, New York, pp 45–52Google Scholar
- Sand O, Enger PS, Karlsen HE, Kudsen FR (2001) Detection of infrasound in fish and behavioral responses to intense infrasound in juvenile salmonids and European silver eels: a minireview. Am Soc Symp 26:183–193Google Scholar
- Sawilowsky S (1985) Robust and power analysis of the 2 × 2 × 2 ANOVA, rank transformation, random normal scores, and expected transformation tests. Unpublished doctoral dissertation, University of South FloridaGoogle Scholar
- Shark Research Institute (2013) http://www.sharkattackfile.net. Accessed 1 May, 2013
- Tavares R (2009) Fishery biology of the Caribbean reef sharks, Carcharhinus perezi (Poey, 1876), in a Caribbean insular platform: Los Roques Archipelago National Park, Venezuela. Pan-Am J Aquat Sci 4:500–512Google Scholar
- van der Waerden BL (1952) Order tests for the two-sample problem and their power. Indag Math 14:453–458Google Scholar