Browsing by Subject "sexual selection"

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    Data for: Species recognition is constrained by chorus noise, but not inconsistency in signal production, in Cope's gray treefrog (Hyla chrysoscelis)
    (2020-06-18) Tanner, Jessie C; Bee, Mark A; jessie.c.tanner@gmail.com; Tanner, Jessie C; University of Minnesota Animal Communication Lab
    Optimal mate choice based on the assessment of communication signals can be constrained by multiple sources of noise. This dataset was created to examine the effects of two possible noise sources: ambient noise caused by the treefrog chorus and the inconsistency in signal production inherent to many animal communication systems. Our data were generated using two-choice phonotaxis tests of female Cope's gray treefrogs.
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    Exploring the form and functions of chimpanzee pant-hoots from basic evolutionary principles.
    (2022-06) Desai, Nisarg
    Researchers have studied chimpanzee vocal communication extensively, focusing on evidence of parallels with human language. This approach has been effective in encouraging vocal communication research and providing some insights about the evolution of language. However, it has obscured our understanding of non-human animal communication by motivating researchers to adopt a problematic conceptual framework that uses complex linguistic phenomena as models for simpler primate vocal communication mechanisms. An approach focusing on basic evolutionary principles involves studying the intimate connection between form and function to obtain insights about the biological and evolutionary origins and mechanisms of traits. Such an approach, when employed for studying chimpanzee vocalizations, may be more fruitful in revealing fundamental factors that may shape their vocalizations. This dissertation extends our knowledge of the forms and functions of chimpanzee vocal communication. I first explored different acoustical and statistical analysis methods for describing the form of vocalizations. Next, I studied connection of the form of chimpanzee vocalization, the pant-hoot, to its possible functions. Using audio recordings and behavioral data from two chimpanzee communities in Gombe National Park, Tanzania, and one chimpanzee community in Kibale National Park, Uganda, I tested if the variation in chimpanzee calls is explained primarily by (i) community membership, or (ii) by individual traits such as age, rank, and health, and (iii) if any of these acoustic cues predicted male mating success. Individual traits better explained the acoustic variation in pant-hoots than community membership. Acoustic variation also reflected male mating success. These findings suggest that sexual selection is a key evolutionary force shaping chimpanzee vocalizations.
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    Frogs Exploit Statistical Regularities in Noisy Acoustic Scenes to Solve Cocktail-Party-Like Problems
    (2017-02-13) Lee, Norman; Ward, Jessica L; Vélez, Alejandro; Micheyl, Christophe; Bee, Mark A; lee33@stolaf.edu; Lee, Norman
    This submission is a supplement to the paper entitled “ Frogs Exploit Statistical Regularities in Noisy Acoustic Scenes to Solve Cocktail-Party-Like Problems” by Lee et al. (2017) published in Current Biology. In this paper, we develop an auditory filterbank inspired by the frog peripheral auditory system to quantify the natural scene statistics of frog breeding choruses. We show that natural chorus noise exhibits a high-level of spectrotemporal correlation (comodulation) among frequencies emphasized in advertisement calls. In 4 psychophysical experiments, we demonstrate that treefrogs can exploit comodulation in background noise to mitigate noise-induced errors in evolutionary critical mate-choice decisions.Frogs experienced fewer errors in recognizing conspecific calls and in selecting calls of high-quality mates in the presence of comodulated noise. This submission includes an implementation of the frog auditory filterbank in Matlab, source data, and other Matlab code used in data analyses to generate the main and supplemental figures presented in Lee et al. (2017).
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    Sexual Selection Constrained: The Expression of Mating Preferences in Acoustically Communicating Animals
    (2018-08) Tanner, Jessie
    Across animal taxa, receivers exert selection on signals and signalers through mate choice. More than a century of research has sought to uncover the targets of this selection and estimate its strength, often using behavioral assays in which receivers discriminate among signals. However, the existence of mating preferences thus discovered does not guarantee their expression in natural signaling contexts. Mating preferences may vary across an individual receiver’s lifetime due to intrinsic factors such as age or mating status. Signals are complex, meaning they comprise multiple components. Individual signalers may differ from one another on the basis of multiple components simultaneously, causing selection on one trait to modulate or reverse the selection on another trait. Additionally, signals are produced repeatedly and traits vary within as well as between signalers, introducing the potential for within-individual variation in signal production to influence the expression of mating preferences. Finally, environmental noise may limit signal recognition, localization, or discrimination in natural settings. Here, I explore these constraints on the expression of mating preferences that impose sexual selection.