Shelling (or conching) is a rare, innovative tool-based foraging strategy observed in bottle nose dolphins (Tursiops sp.).[1] This behavior includes dolphins driving prey into an empty conch shell, and then pouring the shells contents into its mouth.[1][2]

History

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The behavior have been observed in bottlenose dolphin by Simon Allen, of the University of Bristol in England, and Michael Krützen, of the University of Zurich who have surveyed Shark Bay since 2007, collecting both genetic and behavioral data for more than 1,000 dolphins;[3] 19 of which have been observed to use the shelling strategy a total of 42 times.[3] The shelling strategy is rarely observed and may be a new and innovative foraging strategy developed by bottlenose dolphins.[1]

Transmission of Behavior

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Research has shown that the shelling behavior spreads not only via a vertical social transmission mechanism, but a non-vertical mechanism as well.[4][5] Non-vertical social transmission refers to the fact that the behavior can be learned from associates (peer to peer), compared to vertical transmission where learning happens through the mother-calf bond.[4][5] Dolphins have been shown to primarily use vertical transmission as a learning mechanism, and non-vertical transmission is rarely seen.[4]

Implications of the Discovery

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Tool-Usage in Aquatic Life

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Tool-use in regards to animal behavior can be defined as:

the conditional external employment of an unattached or manipulable attached environmental object to alter more efficiently the form, position, or condition of another object, another organism, or the user itself, when the user holds and directly manipulates the tool during or prior to use and is responsible for the proper and effective orientation of the tool.[6]

Tool-use behavior has most commonly been assessed in land-based animals, and is rarely seen in aquatic life.[6] This is not necessarily due to a lack of ability, but rather a lack of need. For example, even though dolphins have larger brains compared to primates and could thus be expected to engage in more tool-use foraging behavior, they have other methods like echolocation for attaining resources.[6] With that being said, conching is just one example of tool-use behavior found in dolphins.[6]

Inter-species Cultural Similarities

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Dolphins are not the only animals who show this cultural, non-vertical transmission mechanism.[4][7][8] It can be seen in members of the Hominidae family, also known as the great apes, which suggests similarities in culture.[4][9] Research has suggested that these cultural similarities may stem from the comparable life history characteristics, cognitive abilities, and social systems between the great apes and dolphins.[4] Specifically, both great apes and dolphins live in highly social communities, which enables considerable levels of social interaction.[9] These high levels of social interaction have been shown to be important in the transmission of socially learned foraging behavior.[4][9]

See also

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References

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  1. ^ a b c Allen, S. J.; Bejder, L.; Krützen, M. (2011). "Why do Indo-Pacific bottlenose dolphins (Tursiops sp.) carry conch shells (Turbinella sp.) in Shark Bay, Western Australia?". Marine Mammal Science. 27 (2): 449–454. Bibcode:2011MMamS..27..449A. doi:10.1111/j.1748-7692.2010.00409.x. ISSN 1748-7692.
  2. ^ Krützen, Michael; Kreicker, Sina; MacLeod, Colin D.; Learmonth, Jennifer; Kopps, Anna M.; Walsham, Pamela; Allen, Simon J. (2014-06-07). "Cultural transmission of tool use by Indo-Pacific bottlenose dolphins ( Tursiops sp.) provides access to a novel foraging niche". Proceedings of the Royal Society B: Biological Sciences. 281 (1784): 20140374. doi:10.1098/rspb.2014.0374. ISSN 0962-8452. PMC 4043097. PMID 24759862.
  3. ^ a b Wu, Katherine J. (2020-06-25). "Dolphins Have an Eating Trick. How They Learn It Is More Surprising". The New York Times. ISSN 0362-4331. Retrieved 2020-06-26.
  4. ^ a b c d e f g Wild, Sonja; Hoppitt, William J.E.; Allen, Simon J.; Krützen, Michael (August 2020). "Integrating Genetic, Environmental, and Social Networks to Reveal Transmission Pathways of a Dolphin Foraging Innovation". Current Biology. 30 (15): 3024–3030.e4. Bibcode:2020CBio...30E3024W. doi:10.1016/j.cub.2020.05.069. ISSN 0960-9822. PMID 32589911. S2CID 220057226.
  5. ^ a b Mann, Janet; Sargeant, Brooke (2003-07-03), "Like mother, like calf: the ontogeny of foraging traditions in wild Indian Ocean bottlenose dolphins (Tursiopssp.)", The Biology of Traditions, Cambridge University Press, pp. 236–266, doi:10.1017/cbo9780511584022.010, ISBN 9780521815970, retrieved 2021-10-25
  6. ^ a b c d Mann, Janet; Patterson, Eric M. (2013-11-19). "Tool use by aquatic animals". Philosophical Transactions of the Royal Society B: Biological Sciences. 368 (1630): 20120424. doi:10.1098/rstb.2012.0424. PMC 4027413. PMID 24101631.
  7. ^ Hobaiter, Catherine; Poisot, Timothée; Zuberbühler, Klaus; Hoppitt, William; Gruber, Thibaud (2014-09-30). de Waal, Frans B. M. (ed.). "Social Network Analysis Shows Direct Evidence for Social Transmission of Tool Use in Wild Chimpanzees". PLOS Biology. 12 (9): e1001960. doi:10.1371/journal.pbio.1001960. ISSN 1545-7885. PMC 4181963. PMID 25268798.
  8. ^ Cornell, Heather N.; Marzluff, John M.; Pecoraro, Shannon (2012-02-07). "Social learning spreads knowledge about dangerous humans among American crows". Proceedings of the Royal Society B: Biological Sciences. 279 (1728): 499–508. doi:10.1098/rspb.2011.0957. ISSN 0962-8452. PMC 3234554. PMID 21715408.
  9. ^ a b c Van Schaik, Carel P. (2003-07-03), "Local traditions in orangutans and chimpanzees: social learning and social tolerance", The Biology of Traditions, Cambridge University Press, pp. 297–328, doi:10.1017/cbo9780511584022.012, ISBN 9780521815970, retrieved 2021-10-25