1,720,979 research outputs found
Sexual selection, breeding behaviour and song communication in house wrens (Troglodytes aedon)
Get PDFElaborated male displays, such as the complex songs of some songbirds, are thought to have evolved via processes of sexual selection addressing two main functions: attracting mates and repelling rivals. House Wrens (Troglodytes aedon) are a good model species because, while not yet systematically studied, the species’ song is noted for being elaborate and complex. The first step in research was to establish basic patterns of male breeding success under natural conditions. The second step was to provide a detailed characterisation of song organisation and diversity and begin to identify dimensions of song performance and complexity likely relevant in female choice of male partners or in male defence of territories against rivals. The final step involved a broad-scale latitudinal study of song patterns across the Americas testing the relevance of these elements of sexual selection on song performance and complexity in House Wrens
The effects of voice pitch and resonances on assessments of speaker size, masculinity, and attractiveness
Get PDFxi, 102 leaves : ill. ; 29 cmThe human voice might have been shaped by sexual selection. Hence, voice fundamental (F0, or pitch) and formant frequencies (Fn, or timbre) are proposed to convey fitness cues germane to rivals and potential mates. First, I confirm the independent effects of F0 and Fn on listeners’ assessments of speaker size, masculinity, and attractiveness. Second, I quantify the just-noticeable differences in both vocal features and then place F0 and Fn cues in conflict by equally discriminable amounts to test their relative influence on such voice-based social judgments. Results revealed a greater relative role of Fn in listeners’ ratings of all three dimensions, suggesting that these dimensions might all be cued more reliably by Fn than F0. Alternatively, given post-hoc principal component analyses that revealed considerable overlap in ratings of size, masculinity, and attractiveness, listeners’ conceptions of these dimensions may not be independent despite a research tradition that assumes they are
The organization and variability of song in Northern House Wrens (Troglodytes aedon parkmanii)
Get PDFx, 111 leaves : ill., maps ; 29 cmHypothesized functions of complex song in birds include a role in mate attraction
and territory defense and, through regional dialects, in genetic substructuring of
populations and speciation. The necessary first step in testing such functions is a detailed
characterization of song organization and variability. This is provided for the Northern
House Wren (Troglodytes aedon), a species noted for complex song, but lacking detailed
descriptions. The species was studied at two sites in Alberta with a sample of 15,000
songs from 15 males. Males sang in long bouts, each song composed of multiple syllable
types and repeated many times before switching. The population repertoire of 27
syllables was almost entirely shared, but used to construct novel repertoires of up to 200
different song types for individual males without evidence of a ceiling. Additional
flexibility and constraints in song construction are discussed in view of the above noted
functions of song complexity
Sound symbolism and the Bouba-Kiki effect : uniting function and mechanism in the search for language universals
Get PDFx, 166 leaves ; 29 cmIn contemporary linguistics, the relationship between word form and meaning is assumed to be arbitrary: words are mutually agreed upon symbolic tokens whose form is entirely unrelated to the objects or events that they denote. Despite the dictum of arbitrariness, examples of correspondences between word form and meaning have been studied periodically over the last century, labeled collectively under the banner of sound symbolism. To investigate the phenomenon of sound symbolism, a series of experiments was conducted on the classic Bouba-Kiki phenomenon. These experiments not only addressed previous methodological and interpretive issues of earlier research, but also entailed a more fine grained approach that allowed for a clearer delineation of the word characteristics responsible for sound symbolic biases. An interpretation of the findings of these experiments is presented that is both in line with potential functional accounts of sound symbolism and also grounded in probable mechanistic instantiations
Radiographic analysis of canine vocal tract anatomy and its implications for human language origins
Get PDFviii, 88 leaves ; 29 cmRadiographic images of the skull and vocal tract of adults from two canid species
were analyzed for two studies addressing functional issues in animal communication and
human language. Study 1 tested the hypothesis that vocal tract length scales reliably with
overall body size such that the acoustic features of vocalizations influenced by vocal tract
length can serve as honest cues to vocalizer body size. Results supported this hypothesis
but emphasized that correlations with body size were better for oral cavity length than for
pharyngeal cavity length. Study 2 tested the hypothesis that laryngeal position can vary in
response to selection on cranio-facial size and shape. Results supported this hypothesis,
finding that the larynx occupies a more descended position in the vocal tract of
individuals with shorter, broader faces compared to longer, narrower faces. The latter
findings have important implications for the origins and evolution of language in humans
Sound symbolism, sonority, and swearing : an affect induction perspective
Get PDFviii, 89 leaves : ill. ; 28 cmThe relationship between word form and word meaning has been debated since early Greek philosophy. Conventionally, the relationship is held to be arbitrary: that there is no natural connection between a word and what it represents (de Saussure 1959). In contrast, examples of sound symbolism undermine this linguistic tenet by demonstrating non-arbitrary word meanings conveyed in details of the acoustic signal of the words themselves. The Affect Induction model of animal communication offers a natural explanation for some forms of sound symbolism in language. According to the Affect Induction model, the physical properties of signals influence receiver affect and behavior in specific ways through relatively direct effects on core sensory, psychological and affective processes. To investigate the possible implications of this model for sound symbolism in human language, a set of studies was conducted on the classic “bouba-kiki” phenomenon. An analysis was subsequently undertaken to extend the results of experiments to several corpuses of real words classically associated with divergent affective themes. Results suggest that the Affect Induction model might account for some forms of sound symbolism, as instantiated in real word usage
The functions and mechanisms of predator-associated vocalisations in North American red squirrels (Tamiasciurus Hudsonicus)
Get PDFxi, 153 leaves : ill. ; 29 cmNorth American red squirrels are a solitary, territorial species that confront various
predators. Previous research proposed that squirrels produce predator-specific, referential
‘seet’ and ‘bark’ alarm calls to aerial and ground predators, respectively. To test this
hypothesis, I examined alarm call production during natural encounters with predators,
conspecific intruders and in a series of predator simulation experiments. Call production
patterns were consistent across all types of disturbance and involved protracted bouts
where both call types were inter-mixed. Hence, the call types were not predator-specific
but rather their patterning reflected the persistence of disturbances of any type. Tests of
alternative call functions further indicated that calls were not actually directed at
conspecifics, but rather at predators and intruders and might function to deter or repel
them directly. These outcomes are consistent with life-history details of red squirrels and
contradict the proposal that this species produces predator-specific, referential alarm
calls
Song sharing in the northern house wren (Troglodytes aedon parkmanii)
Get PDFxi, 102 leaves ; 29 cmThis work provides an initial characterization of song sharing among males in the Northern House Wren (Troglodytes aedon parkmanii). A sample of 21 different males was studied at two different locations across two breeding seasons in southern Alberta, Canada. In total, 35,067 songs were analyzed to assess patterns of song sharing among males within and between study sites and in returning males between years. Virtually all syllable types (n=27) were shared among males. However, they were used to create very large repertoires of mostly unique song types. Absolute levels of song sharing among males was low but song sharing was higher among neighbouring males and decreased with increasing distance between males and across study sites. These patterns are discussed as they relate to important issues in the process of song learning, in the functions of large song repertoires in mate attraction and territory defense, and in the potential formation of dialects in this species
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
- …
