Fork-Tailed Drongos (Dicrurus adsimilis) use different types of mimicked alarm calls in response to different alarm threats

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dc.contributor.advisorRyan, Peter Gen_ZA
dc.contributor.advisorFlower, Thomasen_ZA
dc.contributor.authorAdams, Inge Alisonen_ZA
dc.date.accessioned2015-05-04T07:14:09Z
dc.date.available2015-05-04T07:14:09Z
dc.date.issued2014en_ZA
dc.descriptionIncludes bibliographical references.en_ZA
dc.description.abstractVocal mimicry is a fascinating phenomenon in the animal kingdom, noted in scientific research as early as the 18th century. Approximately 20% of bird species use vocal mimicry, yet very little is understood regarding why species use vocal mimicry, whether it provides functional benefits and in which contexts vocal mimicry is produced. I propose that some of these species produce alarm mimicry in the appropriate alarm contexts, matching the context of call production by the model species whose calls are mimicked. Previous research suggests that alarm mimicry in the appropriate context could provide heterospecifics with information regarding predators that are in the area. Aerial alarm call mimicry could indicate that an aerial predator is present and may cause individuals to flee, while terrestrial mob call mimicry could indicate the presence of a terrestrial predator and could prompt heterospecifics to aid in the mobbing of the predator. I investigate this possibility in the Fork-Tailed Drongo (Dicrurus adsimilis), a species renowned for its use of mimicry of other species alarm calls. Natural alarm responses to predators show that drongos produce alarm mimicry in alarms and never in non-alarm contexts. Overall drongos were more likely to mimic alarms in response to terrestrial predators. I then explored whether drongos use mimicked aerial and terrestrial ‘mobbing’ alarm calls in appropriate aerial or terrestrial predator alarm contexts using recordings of responses by drongos both to natural predators, and to experimental presentations of aerial and terrestrial predator and control models . Drongos were more likely to mimic aerial than ‘mob’ terrestrial alarm calls in response to natural and experimentally presented aerial predators. Conversely, they were more likely to mimic ‘mob’ terrestrial than aerial alarm calls in response to natural and experimentally presented terrestrial predators. Comparison of aerial and mob alarm call mimicry with the drongos production of their own equivalent aerial and terrestrial ‘drongo-specific’ alarm calls, revealed that mimicked and drongo-specific alarm calls were produced in similar contexts. These results support research showing that some bird species produce context-dependent alarm mimicry and the implications for the possible function of alarm call mimicry are discussed.en_ZA
dc.identifier.apacitationAdams, I. A. (2014). <i>Fork-Tailed Drongos (Dicrurus adsimilis) use different types of mimicked alarm calls in response to different alarm threats</i>. (Thesis). University of Cape Town ,Faculty of Science ,Department of Biological Sciences. Retrieved from http://hdl.handle.net/11427/12729en_ZA
dc.identifier.chicagocitationAdams, Inge Alison. <i>"Fork-Tailed Drongos (Dicrurus adsimilis) use different types of mimicked alarm calls in response to different alarm threats."</i> Thesis., University of Cape Town ,Faculty of Science ,Department of Biological Sciences, 2014. http://hdl.handle.net/11427/12729en_ZA
dc.identifier.citationAdams, I. 2014. Fork-Tailed Drongos (Dicrurus adsimilis) use different types of mimicked alarm calls in response to different alarm threats. University of Cape Town.en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Adams, Inge Alison AB - Vocal mimicry is a fascinating phenomenon in the animal kingdom, noted in scientific research as early as the 18th century. Approximately 20% of bird species use vocal mimicry, yet very little is understood regarding why species use vocal mimicry, whether it provides functional benefits and in which contexts vocal mimicry is produced. I propose that some of these species produce alarm mimicry in the appropriate alarm contexts, matching the context of call production by the model species whose calls are mimicked. Previous research suggests that alarm mimicry in the appropriate context could provide heterospecifics with information regarding predators that are in the area. Aerial alarm call mimicry could indicate that an aerial predator is present and may cause individuals to flee, while terrestrial mob call mimicry could indicate the presence of a terrestrial predator and could prompt heterospecifics to aid in the mobbing of the predator. I investigate this possibility in the Fork-Tailed Drongo (Dicrurus adsimilis), a species renowned for its use of mimicry of other species alarm calls. Natural alarm responses to predators show that drongos produce alarm mimicry in alarms and never in non-alarm contexts. Overall drongos were more likely to mimic alarms in response to terrestrial predators. I then explored whether drongos use mimicked aerial and terrestrial ‘mobbing’ alarm calls in appropriate aerial or terrestrial predator alarm contexts using recordings of responses by drongos both to natural predators, and to experimental presentations of aerial and terrestrial predator and control models . Drongos were more likely to mimic aerial than ‘mob’ terrestrial alarm calls in response to natural and experimentally presented aerial predators. Conversely, they were more likely to mimic ‘mob’ terrestrial than aerial alarm calls in response to natural and experimentally presented terrestrial predators. Comparison of aerial and mob alarm call mimicry with the drongos production of their own equivalent aerial and terrestrial ‘drongo-specific’ alarm calls, revealed that mimicked and drongo-specific alarm calls were produced in similar contexts. These results support research showing that some bird species produce context-dependent alarm mimicry and the implications for the possible function of alarm call mimicry are discussed. DA - 2014 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 2014 T1 - Fork-Tailed Drongos (Dicrurus adsimilis) use different types of mimicked alarm calls in response to different alarm threats TI - Fork-Tailed Drongos (Dicrurus adsimilis) use different types of mimicked alarm calls in response to different alarm threats UR - http://hdl.handle.net/11427/12729 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/12729
dc.identifier.vancouvercitationAdams IA. Fork-Tailed Drongos (Dicrurus adsimilis) use different types of mimicked alarm calls in response to different alarm threats. [Thesis]. University of Cape Town ,Faculty of Science ,Department of Biological Sciences, 2014 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/12729en_ZA
dc.language.isoengen_ZA
dc.publisher.departmentDepartment of Biological Sciencesen_ZA
dc.publisher.facultyFaculty of Scienceen_ZA
dc.publisher.institutionUniversity of Cape Town
dc.titleFork-Tailed Drongos (Dicrurus adsimilis) use different types of mimicked alarm calls in response to different alarm threatsen_ZA
dc.typeBachelor Thesis
dc.type.qualificationlevelHonours
dc.type.qualificationnameBSc (Hons)en_ZA
uct.type.filetypeText
uct.type.filetypeImage
uct.type.publicationResearchen_ZA
uct.type.resourceThesisen_ZA
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