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dc.contributor.advisorBalakrishnan, Rohini
dc.contributor.authorAgnihotri, Samira
dc.date.accessioned2017-07-12T09:32:42Z
dc.date.accessioned2018-07-30T14:18:42Z
dc.date.available2017-07-12T09:32:42Z
dc.date.available2018-07-30T14:18:42Z
dc.date.issued2017-07-12
dc.date.submitted2015
dc.identifier.urihttps://etd.iisc.ac.in/handle/2005/2642
dc.identifier.abstracthttp://etd.iisc.ac.in/static/etd/abstracts/3446/G26713-Abs.pdfen_US
dc.description.abstractSound is used as a medium for communication by taxa as varied as insects, fish, amphibians, birds and mammals. In some birds like the suboscines, song is genetically encoded, whereas in parrots, hummingbirds and oscines, it is learnt. The diversity and plasticity of birdsong continues to generate interest amongst ornithologists, and many questions remain unresolved. For instance, why do some species sing hundreds of different songs while others use simple, stereotyped ones for the same purposes? Why do some birds learn not only their own species’ song, but also the songs of heterospecifics? There are several anecdotal reports of such vocal mimicry in wild birds, where a species imitates the song or call of heterospecifics in its natural habitat, but much has yet to be learnt about this intriguing phenomenon. There has been a recent surge of interest and research into avian vocal mimicry. Despite having several species of birds that are known to produce mimicry, there is a dearth of research on this field in India. The Greater Racket-tailed drongo’s loud song and ability to mimic other species of birds with great accuracy has drawn the attention of many birdwatchers, but other than a few phonetic descriptions, no study has focussed on their song. Therefore, this thesis focuses on the structure, contexts and functions of vocal mimicry in this species. In order to understand the functions of vocal mimicry in any species, we require certain fundamental data, which are often overlooked in many studies of bird song. Since this is the first study focusing on the racket-tailed drongo in India, I began with collecting natural history data on the ecology and breeding biology of the species. Then, I attempted to arrive at an objective and quantitative definition and classification of the racket-tailed drongo’s vocal repertoire, especially its mimicry. It is also essential to have information on the contexts in which this mimicry is used. Using a combination of focal animal sampling and sound recordings, I documented the contexts in which the racket-tailed drongo imitates other species in the wild. I also examined the diversity of the species that were mimicked across these contexts. Building on the data from these observations, I used playback experiments to test hypotheses for the functions of mimicry in multiple contexts. Results from these show that greater racket-tailed drongos use mimicry in a flexible manner according to the intended audience. Drongos use two different sets of mimicked calls with distinct syntax directed at conspecifics and heterospecifics respectively, the former in territorial song and the latter to attract members of mixed-species flocks. These results also imply that mimicry may be driven by both sexual and natural selection within the same species, and have implications for the definition of avian vocal mimicry, which remains highly debated.en_US
dc.language.isoen_USen_US
dc.relation.ispartofseriesG27713en_US
dc.subjectGreater Racket-tailed Drongoen_US
dc.subjectAvian Vocal Mimicryen_US
dc.subjectDicrurus paradiseusen_US
dc.subjectBirds - Vocal Mimicryen_US
dc.subjectBird Songsen_US
dc.subjectDrongosen_US
dc.subjectBirds - Vocalizationen_US
dc.subjectGreater Racket-tailed drongo’sen_US
dc.subjectGreater Racket-tailed Drongosen_US
dc.subject.classificationEcologyen_US
dc.titleThe Structure And Function Of The Vocal Repertoire Of The Greater Racket-Tailed Drongo (Dicrurus paradiseus) : Insights Into Avian Vocal Mimicryen_US
dc.typeThesisen_US
dc.degree.namePhDen_US
dc.degree.levelDoctoralen_US
dc.degree.disciplineFaculty of Scienceen_US


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