The role of echolocation in communication in a high duty cycle echolocating bat, Rhinolophus clivosus (Chiroptera: Rhinolophidae): an experimental approach

Simple item page
dc.contributor.advisorJacobs, David Sen_ZA
dc.contributor.advisorBastian, Annaen_ZA
dc.contributor.authorRaw, Roberten_ZA
dc.date.accessioned2017-01-23T07:53:54Z
dc.date.available2017-01-23T07:53:54Z
dc.date.issued2016en_ZA
dc.description.abstractAcoustic communication plays a pivotal role in species recognition across a number of taxa. Species must therefore maintain discrete acoustic signatures to facilitate communication and avoid misidentification. The Acoustic Communication Hypothesis (ACH) thus proposes that in multispecies assemblages, multidimensional acoustic space is partitioned so that each species occupies a discrete acoustic space despite overlap in single parameters (e.g. frequency). Horseshoe bats use echolocation for the purpose of orientation and foraging. However, given the presence of individual and species specific cues in echolocation, it is likely that echolocation also functions to some degree in acoustic communication. This dual function makes echolocation a good model system to investigate the evolution of communication. In support of the ACH recent studies have shown that horseshoe bats are able to discriminate between conspecifics and heterospecifics based on echolocation calls alone even when call frequencies overlap. This suggests that multiple components of echolocation are influential in a bats ability to discriminate between species and indicates a dual function of echolocation in orientation and communication. These multiple components have not until now been identified. Studies have also suggested that preference for echolocation calls in the context of mate choice may influence the evolution of echolocation through sexual selection. Using classical habituation – dishabituation playback experiments, I tested the ability of Geoffroy's horseshoe bat, Rhinolophus clivosus, to discriminate between echolocation calls of heterospecifics with either discrete or overlapping resting frequencies. I subsequently used synthesised calls in which I manipulated individual acoustic parameters, to investigate which call components are involved in discrimination amongst species. Finally, I used a two-alternative choice experiment to investigate preference by R. clivosus to calls of individuals of opposite gender as well as between individuals with high or low body condition during the mating season. Rhinolophus clivosus was able to discriminate readily between echolocation calls with discrete frequencies from different species. When frequencies overlapped, however, the ability of bats to discriminate between species was dependant on additional spectral and temporal components of calls that defined the entire acoustic space occupied by the calls. Consequently, calls that were similar in this multi-parametric acoustic space yielded low levels of discrimination, whereas calls separated in acoustic space yielded high levels of discrimination. This study provides the first experimental evidence of call components, other than frequency, that may play a role in species discrimination and questions earlier reports that bats use echolocation in mate choice. In support of the communicative role of echolocation, bats were also able to discriminate between calls from bats that differed in their body condition, indicating echolocation might represent an honest signal of mate quality and thus a function in mate choice. However, despite this, R. clivosus showed no preference or association based on gender or body condition. The results of this study suggest that despite having the ability to use echolocation to discriminate amongst conspecifics, these bats do not base mate choice on echolocation call components.en_ZA
dc.identifier.apacitationRaw, R. (2016). <i>The role of echolocation in communication in a high duty cycle echolocating bat, Rhinolophus clivosus (Chiroptera: Rhinolophidae): an experimental approach</i>. (Thesis). University of Cape Town ,Faculty of Science ,Department of Biological Sciences. Retrieved from http://hdl.handle.net/11427/22909en_ZA
dc.identifier.chicagocitationRaw, Robert. <i>"The role of echolocation in communication in a high duty cycle echolocating bat, Rhinolophus clivosus (Chiroptera: Rhinolophidae): an experimental approach."</i> Thesis., University of Cape Town ,Faculty of Science ,Department of Biological Sciences, 2016. http://hdl.handle.net/11427/22909en_ZA
dc.identifier.citationRaw, R. 2016. The role of echolocation in communication in a high duty cycle echolocating bat, Rhinolophus clivosus (Chiroptera: Rhinolophidae): an experimental approach. University of Cape Town.en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Raw, Robert AB - Acoustic communication plays a pivotal role in species recognition across a number of taxa. Species must therefore maintain discrete acoustic signatures to facilitate communication and avoid misidentification. The Acoustic Communication Hypothesis (ACH) thus proposes that in multispecies assemblages, multidimensional acoustic space is partitioned so that each species occupies a discrete acoustic space despite overlap in single parameters (e.g. frequency). Horseshoe bats use echolocation for the purpose of orientation and foraging. However, given the presence of individual and species specific cues in echolocation, it is likely that echolocation also functions to some degree in acoustic communication. This dual function makes echolocation a good model system to investigate the evolution of communication. In support of the ACH recent studies have shown that horseshoe bats are able to discriminate between conspecifics and heterospecifics based on echolocation calls alone even when call frequencies overlap. This suggests that multiple components of echolocation are influential in a bats ability to discriminate between species and indicates a dual function of echolocation in orientation and communication. These multiple components have not until now been identified. Studies have also suggested that preference for echolocation calls in the context of mate choice may influence the evolution of echolocation through sexual selection. Using classical habituation – dishabituation playback experiments, I tested the ability of Geoffroy's horseshoe bat, Rhinolophus clivosus, to discriminate between echolocation calls of heterospecifics with either discrete or overlapping resting frequencies. I subsequently used synthesised calls in which I manipulated individual acoustic parameters, to investigate which call components are involved in discrimination amongst species. Finally, I used a two-alternative choice experiment to investigate preference by R. clivosus to calls of individuals of opposite gender as well as between individuals with high or low body condition during the mating season. Rhinolophus clivosus was able to discriminate readily between echolocation calls with discrete frequencies from different species. When frequencies overlapped, however, the ability of bats to discriminate between species was dependant on additional spectral and temporal components of calls that defined the entire acoustic space occupied by the calls. Consequently, calls that were similar in this multi-parametric acoustic space yielded low levels of discrimination, whereas calls separated in acoustic space yielded high levels of discrimination. This study provides the first experimental evidence of call components, other than frequency, that may play a role in species discrimination and questions earlier reports that bats use echolocation in mate choice. In support of the communicative role of echolocation, bats were also able to discriminate between calls from bats that differed in their body condition, indicating echolocation might represent an honest signal of mate quality and thus a function in mate choice. However, despite this, R. clivosus showed no preference or association based on gender or body condition. The results of this study suggest that despite having the ability to use echolocation to discriminate amongst conspecifics, these bats do not base mate choice on echolocation call components. DA - 2016 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 2016 T1 - The role of echolocation in communication in a high duty cycle echolocating bat, Rhinolophus clivosus (Chiroptera: Rhinolophidae): an experimental approach TI - The role of echolocation in communication in a high duty cycle echolocating bat, Rhinolophus clivosus (Chiroptera: Rhinolophidae): an experimental approach UR - http://hdl.handle.net/11427/22909 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/22909
dc.identifier.vancouvercitationRaw R. The role of echolocation in communication in a high duty cycle echolocating bat, Rhinolophus clivosus (Chiroptera: Rhinolophidae): an experimental approach. [Thesis]. University of Cape Town ,Faculty of Science ,Department of Biological Sciences, 2016 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/22909en_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.subject.otherBiological Sciencesen_ZA
dc.titleThe role of echolocation in communication in a high duty cycle echolocating bat, Rhinolophus clivosus (Chiroptera: Rhinolophidae): an experimental approachen_ZA
dc.typeDoctoral Thesis
dc.type.qualificationlevelDoctoral
dc.type.qualificationnamePhDen_ZA
uct.type.filetypeText
uct.type.filetypeImage
uct.type.publicationResearchen_ZA
uct.type.resourceThesisen_ZA
Files
Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
thesis_sci_2016_raw_robert (1).pdf
Size:
1.82 MB
Format:
Adobe Portable Document Format
Description:
Download
Collections
PhD / Doctoral