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Gerald Borgia - One of the best experts on this subject based on the ideXlab platform.

  • (Ptilonorhynchus violaceus)
    2015
    Co-Authors: Gail L. Patricelli, J. Albert, Gerald Borgia
    Abstract:

    signals enhance the efficiency of mate assessment in satin Bowerbird

  • Behavioral Ecology
    2014
    Co-Authors: Gerald Borgia
    Abstract:

    doi:10.1093/beheco/arn010 Experimental blocking of UV reflectance does not influence use of off-body display elements by satin Bowerbird

  • tests of the kin selection model of mate choice and inbreeding avoidance in satin Bowerbirds
    Behavioral Ecology, 2014
    Co-Authors: Seth W Coleman, Gail L. Patricelli, Sheila M Reynolds, Michael J Braun, Gerald Borgia
    Abstract:

    In typically outbreeding species, females can avoid a reduction in offspring fitness by choosing unrelated sires. However, the kin selection model of mate choice suggests that it may be adaptive to mate with relatives to gain inclusive fitness benefits, especially in lekking species. Several studies have shown that females tend to mate with relatives, but the detailed behavioral data necessary to determine whether this reflects an active preference is difficult to acquire. We test the hypotheses that females actively preferred or avoided relatives in mate choice in satin Bowerbirds (Ptilonorhynchus violaceus), a lekking species in which comprehensive observations of natural mate choice were obtained using automated video cameras positioned at bowers. We identified specific males that were sampled by individual females and assessed whether relatedness influenced their acceptance or rejection as mates. We found no consistent effect of relatedness on mate choice across years or among multiple stages of mate choice. In 2 of 6 years, females copulated with relatives at or above the half-sibling level significantly more often than expected, but this was attributed to females searching for mates in areas populated by relatives, and not to an active preference for relatives. Furthermore, we found no evidence for inbreeding avoidance through mate choice discrimination or sex-biased dispersal.

  • bower paint removal leads to reduced female visits suggesting bower paint functions as a chemical signal
    Animal Behaviour, 2013
    Co-Authors: Reimi E Hicks, Archer Larned, Gerald Borgia
    Abstract:

    The multifaceted courtship display of male satin Bowerbirds, Ptilonorhynchus violaceus, involves several elements that have been studied in detail. However, one of their most unique display elements, bower painting, has received relatively little attention despite males' large investment of time in this behaviour. Male Bowerbirds chew plant material and apply the resulting mixture of masticated vegetation and male saliva or ‘bower paint’ to a chest-high band inside their bower walls. Searching females taste this paint, suggesting that paint may be a chemosensory signal. We used both behavioural observations and experimental approaches to examine predictions made by two hypotheses for the function of bower paint. We measured natural variation in paint quantity to investigate whether quantity of paint at bowers is related to other male display traits, male mating success and male physical condition. We also investigated whether males and females are affected by experimental removal of bower paint. Additionally, we assessed male response to paint transplants from other individuals. We found a significant correlation between the amount of paint and a composite estimate of several other measures known to indicate bower and decoration display quality. Also, males whose bowers underwent experimental removal of paint had fewer females return for second courtships and copulations than did control males. This result provides the first experimental evidence that females respond to bower paint. These findings establish that bower paint is a trait that affects mate-searching decisions by females and demonstrates that the quantity of bower paint is important in attracting females.

  • Limited variation in visual sensitivity among Bowerbird species suggests that there is no link between spectral tuning and variation in display colouration
    Journal of Experimental Biology, 2012
    Co-Authors: Brian J. Coyle, Nathan S. Hart, Karen L. Carleton, Gerald Borgia
    Abstract:

    SUMMARY Variation in visual spectral tuning has evolved in concert with signal colour in some taxa, but there is limited evidence of this pattern in birds. To further investigate this possibility, we compared spectral sensitivity among Bowerbird species that occupy different visual habitats and are highly diverged in plumage and decoration colour displays, which are important in mate choice and possibly reproductive isolation. Microspectrophotometry of violet-, short-, medium- and long-wavelength-sensitive cones revealed no significant interspecific variation in visual pigment peak spectral absorbance values that ranged between 404–410, 454, 503–511 and 558–568 nm, respectively. Mean cut-off wavelength values for C-, Y-, R- and P-type coloured oil droplets were 418–441, 508–523, 558–573 and 412–503 nm, respectively, with values at longer wavelengths in ventral compared with dorsal retina cones. Low ocular media mid-wavelength transmission values (340–352 nm) suggest that Bowerbirds may represent a transitional stage in the evolution from the ancestral violet-sensitive- to the derived ultraviolet-sensitive-type short-wavelength-sensitive-1-based visual system found in younger passerine lineages. Sequence data obtained for rod opsin and four cone opsin genes were identical at key tuning sites, except for an interspecific leucine-52-alanine polymorphism in the short-wavelength-sensitive 2 opsin. There was no obvious relationship between relative proportions of cone classes and either visual habitat or display colour. Overall, we detected little interspecific variation in Bowerbird spectral sensitivity and no association between sensitivity and display diversity, which is consistent with the general trend among avian taxa.

Belinda S W Chang - One of the best experts on this subject based on the ideXlab platform.

  • functional characterization of spectral tuning mechanisms in the great Bowerbird short wavelength sensitive visual pigment sws1 and the origins of uv violet vision in passerines and parrots
    BMC Evolutionary Biology, 2013
    Co-Authors: Ilke Van Hazel, John A Endler, Amir Sabouhanian, Lainy B Day, Belinda S W Chang
    Abstract:

    One of the most striking features of avian vision is the variation in spectral sensitivity of the short wavelength sensitive (SWS1) opsins, which can be divided into two sub-types: violet- and UV- sensitive (VS & UVS). In birds, UVS has been found in both passerines and parrots, groups that were recently shown to be sister orders. While all parrots are thought to be UVS, recent evidence suggests some passerine lineages may also be VS. The great Bowerbird (Chlamydera nuchalis) is a passerine notable for its courtship behaviours in which males build and decorate elaborate bower structures. The great Bowerbird SWS1 sequence possesses an unusual residue combination at known spectral tuning sites that has not been previously investigated in mutagenesis experiments. In this study, the SWS1 opsin of C. nuchalis was expressed along with a series of spectral tuning mutants and ancestral passerine SWS1 pigments, allowing us to investigate spectral tuning mechanisms and explore the evolution of UV/violet sensitivity in early passerines and parrots. The expressed C. nuchalis SWS1 opsin was found to be a VS pigment, with a λmax of 403 nm. Bowerbird SWS1 mutants C86F, S90C, and C86S/S90C all shifted λmax into the UV, whereas C86S had no effect. Experimentally recreated ancestral passerine and parrot/passerine SWS1 pigments were both found to be VS, indicating that UV sensitivity evolved independently in passerines and parrots from a VS ancestor. Our mutagenesis studies indicate that spectral tuning in C. nuchalis is mediated by mechanisms similar to those of other birds. Interestingly, our ancestral sequence reconstructions of SWS1 in landbird evolution suggest multiple transitions from VS to UVS, but no instances of the reverse. Our results not only provide a more precise prediction of where these spectral sensitivity shifts occurred, but also confirm the hypothesis that birds are an unusual exception among vertebrates where some descendants re-evolved UVS from a violet type ancestor. The re-evolution of UVS from a VS type pigment has not previously been predicted elsewhere in the vertebrate phylogeny.

  • Functional characterization of spectral tuning mechanisms in the great Bowerbird short-wavelength sensitive visual pigment (SWS1), and the origins of UV/violet vision in passerines and parrots.
    eScholarship University of California, 2013
    Co-Authors: Van Hazel Ilke, Endler, John A., Sabouhanian Amir, Day Lainy, Belinda S W Chang
    Abstract:

    BackgroundOne of the most striking features of avian vision is the variation in spectral sensitivity of the short wavelength sensitive (SWS1) opsins, which can be divided into two sub-types: violet- and UV- sensitive (VS & UVS). In birds, UVS has been found in both passerines and parrots, groups that were recently shown to be sister orders. While all parrots are thought to be UVS, recent evidence suggests some passerine lineages may also be VS. The great Bowerbird (Chlamydera nuchalis) is a passerine notable for its courtship behaviours in which males build and decorate elaborate bower structures.ResultsThe great Bowerbird SWS1 sequence possesses an unusual residue combination at known spectral tuning sites that has not been previously investigated in mutagenesis experiments. In this study, the SWS1 opsin of C. nuchalis was expressed along with a series of spectral tuning mutants and ancestral passerine SWS1 pigments, allowing us to investigate spectral tuning mechanisms and explore the evolution of UV/violet sensitivity in early passerines and parrots. The expressed C. nuchalis SWS1 opsin was found to be a VS pigment, with a λmax of 403 nm. Bowerbird SWS1 mutants C86F, S90C, and C86S/S90C all shifted λmax into the UV, whereas C86S had no effect. Experimentally recreated ancestral passerine and parrot/passerine SWS1 pigments were both found to be VS, indicating that UV sensitivity evolved independently in passerines and parrots from a VS ancestor.ConclusionsOur mutagenesis studies indicate that spectral tuning in C. nuchalis is mediated by mechanisms similar to those of other birds. Interestingly, our ancestral sequence reconstructions of SWS1 in landbird evolution suggest multiple transitions from VS to UVS, but no instances of the reverse. Our results not only provide a more precise prediction of where these spectral sensitivity shifts occurred, but also confirm the hypothesis that birds are an unusual exception among vertebrates where some descendants re-evolved UVS from a violet type ancestor. The re-evolution of UVS from a VS type pigment has not previously been predicted elsewhere in the vertebrate phylogeny

John A Endler - One of the best experts on this subject based on the ideXlab platform.

  • How do great Bowerbirds construct perspective illusions?
    'The Royal Society', 2017
    Co-Authors: La Kelley, John A Endler
    Abstract:

    This is the final version of the article. Available from the Royal Society via the DOI in this record.Many animals build structures to provide shelter, avoid predation, attract mates or house offspring, but the behaviour and potential cognitive processes involved during building are poorly understood. Great Bowerbird (Ptilinorhynchus nuchalis) males build and maintain display courts by placing tens to hundreds of objects in a positive size-distance gradient. The visual angles created by the gradient create a forced perspective illusion that females can use to choose a mate. Although the quality of illusion is consistent within males it varies among males, which may reflect differences in how individuals reconstruct their courts. We moved all objects off display courts to determine how males reconstructed the visual illusion. We found that all individuals rapidly created the positive size-distance gradient required for forced perspective within the first 10 objects placed. Males began court reconstruction by placing objects in the centre of the court and then placing objects further out, a technique commonly used when humans lay mosaics. The number of objects present after 72 hours was not related to mating success or the quality of the illusion, indicating that male skill at arranging objects rather than absolute number of objects appears to be important. We conclude that differences arise in the quality of forced perspective illusions despite males using the same technique to reconstruct their courts.LAK received funding from the People Programme (Marie Curie Actions) of the 459 European Union’s Seventh Framework Programme (FP7/2007-2013) under REA 460 grant agreement PIIF-GA-2012-327423. This research was partially funded by 461 Editor’s fees from Springer-Verlag and Deakin University to JAE

  • Mean differences between sets of residuals and permutation test probabilities of the differences from How do great Bowerbirds construct perspective illusions?
    2016
    Co-Authors: Laura A Kelley, John A Endler
    Abstract:

    Many animals build structures to provide shelter, avoid predation, attract mates or house offspring, but the behaviour and potential cognitive processes involved during building are poorly understood. Great Bowerbird (Ptilinorhynchus nuchalis) males build and maintain display courts by placing tens to hundreds of objects in a positive size–distance gradient. The visual angles created by the gradient create a forced perspective illusion that females can use to choose a mate. Although the quality of illusion is consistent within males, it varies among males, which may reflect differences in how individuals reconstruct their courts. We moved all objects off display courts to determine how males reconstructed the visual illusion. We found that all individuals rapidly created the positive size–distance gradient required for forced perspective within the first 10 objects placed. Males began court reconstruction by placing objects in the centre of the court and then placing objects further out, a technique commonly used when humans lay mosaics. The number of objects present after 72 h was not related to mating success or the quality of the illusion, indicating that male skill at arranging objects rather than absolute number of objects appears to be important. We conclude that differences arise in the quality of forced perspective illusions despite males using the same technique to reconstruct their courts

  • Electronic supplementary material is available
    2014
    Co-Authors: John A Endler
    Abstract:

    Keywords: Bowerbird, sexual display, visual effects, Author for correspondence

  • functional characterization of spectral tuning mechanisms in the great Bowerbird short wavelength sensitive visual pigment sws1 and the origins of uv violet vision in passerines and parrots
    BMC Evolutionary Biology, 2013
    Co-Authors: Ilke Van Hazel, John A Endler, Amir Sabouhanian, Lainy B Day, Belinda S W Chang
    Abstract:

    One of the most striking features of avian vision is the variation in spectral sensitivity of the short wavelength sensitive (SWS1) opsins, which can be divided into two sub-types: violet- and UV- sensitive (VS & UVS). In birds, UVS has been found in both passerines and parrots, groups that were recently shown to be sister orders. While all parrots are thought to be UVS, recent evidence suggests some passerine lineages may also be VS. The great Bowerbird (Chlamydera nuchalis) is a passerine notable for its courtship behaviours in which males build and decorate elaborate bower structures. The great Bowerbird SWS1 sequence possesses an unusual residue combination at known spectral tuning sites that has not been previously investigated in mutagenesis experiments. In this study, the SWS1 opsin of C. nuchalis was expressed along with a series of spectral tuning mutants and ancestral passerine SWS1 pigments, allowing us to investigate spectral tuning mechanisms and explore the evolution of UV/violet sensitivity in early passerines and parrots. The expressed C. nuchalis SWS1 opsin was found to be a VS pigment, with a λmax of 403 nm. Bowerbird SWS1 mutants C86F, S90C, and C86S/S90C all shifted λmax into the UV, whereas C86S had no effect. Experimentally recreated ancestral passerine and parrot/passerine SWS1 pigments were both found to be VS, indicating that UV sensitivity evolved independently in passerines and parrots from a VS ancestor. Our mutagenesis studies indicate that spectral tuning in C. nuchalis is mediated by mechanisms similar to those of other birds. Interestingly, our ancestral sequence reconstructions of SWS1 in landbird evolution suggest multiple transitions from VS to UVS, but no instances of the reverse. Our results not only provide a more precise prediction of where these spectral sensitivity shifts occurred, but also confirm the hypothesis that birds are an unusual exception among vertebrates where some descendants re-evolved UVS from a violet type ancestor. The re-evolution of UVS from a VS type pigment has not previously been predicted elsewhere in the vertebrate phylogeny.

  • illusions promote mating success in great Bowerbirds
    Science, 2012
    Co-Authors: Laura A Kelley, John A Endler
    Abstract:

    Sexual selection studies normally compare signal strengths, but signal components and sensory processing may interact to create misleading or attention-capturing illusions. Visual illusions can be produced by altering object and scene geometry in ways that trick the viewer when seen from a particular direction. Male great Bowerbirds actively maintain size-distance gradients of objects on their bower courts that create forced-perspective illusions for females viewing their displays from within the bower avenue. We show a significant relationship between mating success and the female's view of the gradient; this view explains substantially more variance in mating success than the strength of the gradients. Illusions may be widespread in other animals because males of most species display to females with characteristic orientation and distance, providing excellent conditions for illusions.

Bush, Sarah E. - One of the best experts on this subject based on the ideXlab platform.

Ilke Van Hazel - One of the best experts on this subject based on the ideXlab platform.

  • functional characterization of spectral tuning mechanisms in the great Bowerbird short wavelength sensitive visual pigment sws1 and the origins of uv violet vision in passerines and parrots
    BMC Evolutionary Biology, 2013
    Co-Authors: Ilke Van Hazel, John A Endler, Amir Sabouhanian, Lainy B Day, Belinda S W Chang
    Abstract:

    One of the most striking features of avian vision is the variation in spectral sensitivity of the short wavelength sensitive (SWS1) opsins, which can be divided into two sub-types: violet- and UV- sensitive (VS & UVS). In birds, UVS has been found in both passerines and parrots, groups that were recently shown to be sister orders. While all parrots are thought to be UVS, recent evidence suggests some passerine lineages may also be VS. The great Bowerbird (Chlamydera nuchalis) is a passerine notable for its courtship behaviours in which males build and decorate elaborate bower structures. The great Bowerbird SWS1 sequence possesses an unusual residue combination at known spectral tuning sites that has not been previously investigated in mutagenesis experiments. In this study, the SWS1 opsin of C. nuchalis was expressed along with a series of spectral tuning mutants and ancestral passerine SWS1 pigments, allowing us to investigate spectral tuning mechanisms and explore the evolution of UV/violet sensitivity in early passerines and parrots. The expressed C. nuchalis SWS1 opsin was found to be a VS pigment, with a λmax of 403 nm. Bowerbird SWS1 mutants C86F, S90C, and C86S/S90C all shifted λmax into the UV, whereas C86S had no effect. Experimentally recreated ancestral passerine and parrot/passerine SWS1 pigments were both found to be VS, indicating that UV sensitivity evolved independently in passerines and parrots from a VS ancestor. Our mutagenesis studies indicate that spectral tuning in C. nuchalis is mediated by mechanisms similar to those of other birds. Interestingly, our ancestral sequence reconstructions of SWS1 in landbird evolution suggest multiple transitions from VS to UVS, but no instances of the reverse. Our results not only provide a more precise prediction of where these spectral sensitivity shifts occurred, but also confirm the hypothesis that birds are an unusual exception among vertebrates where some descendants re-evolved UVS from a violet type ancestor. The re-evolution of UVS from a VS type pigment has not previously been predicted elsewhere in the vertebrate phylogeny.