Terminal Syllables Research Articles

Timing during transitions in Bengalese finch song: implications for motor sequencing.

To investigate mechanisms of action sequencing, we examined the relationship between timing and sequencing of syllables in Bengalese finch song. An individual's song comprises acoustically distinct syllables organized into probabilistic sequences: a given syllable potentially can transition to several different syllables (divergence points), and several different syllables can transition to a given syllable (convergence points). In agreement with previous studies, we found that more probable transitions at divergence points occur with shorter intersyllable gaps. One intuition for this relationship is that selection between syllables reflects a competitive branching process, in which stronger links to one syllable lead to both higher probabilities and shorter latencies for transitions to that syllable vs. competing alternatives. However, we found that simulations of competitive race models result in overlapping winning-time distributions for competing outcomes and fail to replicate the strong negative correlation between probability and gap duration found in song data. Further investigation of song structure revealed strong positive correlation between gap durations for transitions that share a common convergent point. Such transitions are not related by a common competitive process, but instead reflect a common terminal syllable. In contrast to gap durations, transition probabilities were not correlated at convergence points. Together, our data suggest that syllable selection happens early during the gap, with gap timing determined chiefly by the latency to syllable initiation. This may result from a process in which probabilistic sequencing is first stabilized, followed by a shortening of the latency to syllables that are sung more often.NEW & NOTEWORTHY Bengalese finch songs consist of probabilistic sequences of syllables. Previous studies revealed a strong negative correlation between transition probability and the duration of intersyllable gaps. We show here that the negative correlation is inconsistent with previous suggestions that timing at syllable transitions is governed by a race between competing alternatives. Rather, the data suggest that syllable selection happens early during the gap, with gap timing determined chiefly by the latency to syllable initiation.

Modeling Pauses for Synthesis of Storytelling Style Speech Using Unsupervised Word Features

Abstract In the storytelling style speech pauses or phrase breaks play a significant role in introducing suspense and climax in the story. More often pauses are provided by a storyteller to capture the audience's attention by emphasizing keywords, focusing emotion-salient words, and to separate key phrases in an utterance. The goal of the work presented in this paper is to predict the location of pauses, in an utterance synthesized by a Story Text-To-Speech (TTS) system using unsupervised features at word-level. Traditional methods for predicting pauses uses the foremost linguistic features like Parts-of-Speech (POS) tags, chunking information or terminal syllables, etc. These methods presuppose the availability of linguistic knowledge by an automatic tagger or manually annotated corpus. However, this information's are not readily available in case of Indian Languages. Manually annotating the text with this linguistic information is quite hectic and time consuming. Also, these pieces of information's do not capture the co-occurrence statistics of words. Hence, we propose a framework for integrating the Story TTS with proposed pause prediction module. In this module, an unlabeled text corpus is used to extract, the continuous-valued world-level features to model the pause patterns in storytelling speech. A set of story-specific (SS) features are introduced for capturing story-semantic information based on pause pattern. A various combination of pause predictions systems is- proposed such as B, POS, U, POS+SS and U+SS. These systems are evaluated objectively by F-1 Score.

Rapid change in a Type I song dialect of Hermit Warblers(Setophaga occidentalis)

Although first-category (Type I) songs of some wood-warblers (Parulidae) are structurally stable over time and range, we document a rapid change in the song of a population of Hermit Warblers (Setophaga occidentalis) in northern Oregon. Type I songs on Mount Hood were recorded in 1990 and 1992. When the population was revisited in 2003, the birds in the area sang a different Type I song. The distinctive terminal syllable was absent, the introductory series of repeated syllables had differentiated into two parts, and the first phrase had increased in duration. In 2004, an area within a 20-km radius centered on the original population was systematically searched; from 2004 to 2006, selected areas were searched up to 65 km distant. Five scattered individuals in a limited area were found singing the earlier song 23–28 km to the east, at the periphery of the area dominated by the new song. The differences between the earlier and later songs, which are smaller than differences with neighboring dialects, suggest that the song changed within the current population rather than via displacement by individuals from an adjacent song population. Structural change over time in a Type I song of a wood-warbler over an area larger than a neighborhood has not been previously documented.

A new species of wren (Troglodytidae:Thryophilus) from the dry Cauca River Canyon, northwestern Colombia

ABSTRACT . We describe a new species of wren in the genus Thryophilus (Troglodytidae) based on analysis of morphological, vocal, and genetic variation. Individuals of the new species are readily separated in the field or the museum from those of any other wren species, including its closest relatives T. rufalbus and T. nicefori, by a combination of traits including, but not limited to, plumage coloration of the upperparts, the pattern of barring on the wings and tail, overall smaller body size, a richer repertoire of syllable types, shorter trills, and distinctive terminal syllables. The new species is allopatrically distributed in relation to its congeners, being restricted to the dry Cauca River Canyon, a narrow inter-Andean valley enclosed by the Nechi Refuge rainforests and the northern sectors of the Western and Central Andes of Colombia. Individuals or pairs have been found only in remnant patches of dry forest and scrub at 250– 850 m elevation. This newly discovered species is uncommon and threaten...

Variation of Type B Song in the Endangered Golden-Cheeked Warbler (Dendroica chrysoparia)

The Golden-cheeked Warbler (Dendroica chrysoparia), a member of the Parulidae, uses a two-category song system referred to as Type A and Type B. However, songs recorded from adult males in Bexar County, Texas, USA, did not resemble the typical A or B songs reported for this species. We report an analysis of these atypical songs from six adult males. Quantitative features of the measured songs and syllable structure suggest this atypical song is more comparable to a B song than an A song with some modifications. The atypical song has dropped a terminal syllable of the known B song, and selectively modified one of the syllables to include frequency modulations (up and down slurs). Further, the known B song was not heard in the investigated sites. We conclude the atypical song is a variant of the B song.

Bachelor and paired male rufous-and-white wrens use different singing strategies

To attract a breeding partner, males may behave differently when they are bachelors compared to when they are paired. Comparisons between groups of paired males versus groups of unpaired males in temperate-breeding animals have revealed such differences in signalling behaviour. Few studies, however, have explored how individual males alter their signalling behaviour with changes in pairing status, and very few investigations have explored paired versus unpaired male behaviour in tropical animals. During a 5-year study in Costa Rica, we analysed changes in the singing behaviour of male rufous-and-white wrens (Thryothorus rufalbus) when they were paired and when they were bachelors. We compared three aspects of male vocal behaviour: gross differences in song output, variation in repertoire use and differences in song structure. Males as bachelors had significantly higher song output and switched song types less frequently. Contrary to our expectation, bachelors sang significantly fewer song types from their repertoire compared to when those same males had a breeding partner. Songs sung by bachelor males were higher in syllabic diversity and had broader-bandwidth terminal syllables than the songs those males sang only when paired. Within song types, the fine structure of songs remained consistent across pairing status. Our results demonstrate that males change their singing behaviour with pairing status, delivering songs at a higher rate but with less variety when they are bachelors. Rufous-and-white wrens are renowned for their vocal duets, and we discuss the pattern of repertoire use in light of their duetting behaviour. These results enhance our understanding of how male behaviour varies with pairing status and the importance of vocal signalling behaviour in socially monogamous tropical animals.

VOCAL BEHAVIOR OF THE CRITICALLY ENDANGERED NICEFORO'S WREN (THRYOTHORUS NICEFORI)

Abstract Niceforo's Wren (Thryothorus nicefori) is a critically endangered songbird endemic to dry forests of the Chicamocha Valley in central Colombia. Discovered in 1946 and red-listed by the IUCN since 1988, Niceforo's Wren faces a threat of extinction because of its limited habitat range and increasing deforestation for agriculture and livestock. This species has been poorly studied, and its vocal behavior is yet undescribed. We provide the first description of the vocalizations of Niceforo's Wren, based on analyses of recordings from 29 individuals (more than half of all estimated living individuals of this species). We examined the fine structure of their songs, the pattern of solo and duet singing behavior, and the song repertoire size of males and females. Both sexes produce solo songs, coordinated vocal duets, and a variety of calls. Songs have a stereotyped syntax including one or more introductory syllables, a trill of rapidly repeated syllables, and a frequency-modulated terminal syllable. M...

Species Differences in the Songs of the Critically Endangered Niceforo's Wren and the Related Rufous-and-White Wren

Abstract Niceforo's Wrens (Thryothorus nicefori) and Rufous-and-white Wrens (Thryothorus rufalbus) are closely related Neotropical birds. Niceforo's Wrens, critically endangered endemic Colombian songbirds, are generally considered a sister species to Rufous-and-white Wrens, although some have suggested that they may represent a well-marked race. A careful comparison of the two taxa has never been conducted. Here we present a thorough study of the songs of male Niceforo's and Rufous-and-white Wrens based on recordings collected throughout both species' geographic ranges. Both species sing low-pitched songs composed of varied pure tone whistles. Niceforo's Wren songs are shorter and simpler with fewer syllables and syllable types; they have higher frequency trills and terminal syllables; and they have distinctive terminal syllables with a broader bandwidth, higher frequency of maximum amplitude, and a larger number of frequency modulations. Discriminant analysis based on fine structural details of songs differentiates the two species. In a subspecies-level discriminant analysis, all five subspecies of Rufous-and-white Wren cluster together and are distinct from Niceforo's Wren. Comparisons of morphometric measurements and plumage features reveal parallel differences in body size (Niceforo's Wrens are larger for most measurements) and plumage color (Niceforo's Wrens are more gray than Rufous-and-white Wrens). This study is the first to compare Rufous-and-white versus Niceforo's Wrens with a quantitative approach and supports the idea that these taxa are best understood as distinct species.

SPECIES DIFFERENCES IN THE SONGS OF THE CRITICALLY ENDANGERED NICEFORO'S WREN AND THE RELATED RUFOUS-AND-WHITE WREN

Abstract Niceforo's Wrens (Thryothorus nicefori) and Rufous-and-white Wrens (Thryothorus rufalbus) are closely related Neotropical birds. Niceforo's Wrens, critically endangered endemic Colombian songbirds, are generally considered a sister species to Rufous-and-white Wrens, although some have suggested that they may represent a well-marked race. A careful comparison of the two taxa has never been conducted. Here we present a thorough study of the songs of male Niceforo's and Rufous-and-white Wrens based on recordings collected throughout both species' geographic ranges. Both species sing low-pitched songs composed of varied pure tone whistles. Niceforo's Wren songs are shorter and simpler with fewer syllables and syllable types; they have higher frequency trills and terminal syllables; and they have distinctive terminal syllables with a broader bandwidth, higher frequency of maximum amplitude, and a larger number of frequency modulations. Discriminant analysis based on fine structural details of songs di...

Sexually antithetical song structure in a duet singing wren

Summary Black-bellied wrens (Thryothorus fasciatoventris) use loud songs to communicate sex over long distances. We compared male and female songs recorded from a central Panamanian population of black-bellied wrens. All nine measured features differed significantly between the sexes. Males sang lower fundamental frequencies than females, but this difference cannot be explained by simple body size-frequency scaling. A discriminant function analysis correctly discriminated the singer’s sex for all songs in the analysis. When viewed as sonograms, the terminal syllables of male and female songs exhibited opposite structure ‐ all male songs ended in V-shaped syllables, and all female songs ended in arc-shaped syllables. The degree and character of dimorphism lead us to describe song structure in this population as ‘sexually antithetical’. Variation in song dimorphism throughout this species’ range provides an excellent opportunity to test the hypothesis that signal degradation during transmission selects for divergent signal structure.

Age-dependent health status and song characteristics in the barn swallow

Bird song has been hypothesized to evolve, partly, to signal health status of males, and song features should therefore correlate with parasite load. Immune function, parasitism, and secondary sexual characters can, however, differ between age classes, and any apparent relationship between song and parasite loads can be the result of systematic age effects. We tested for an age-dependent relationship between sexually selected characters and measures of parasitism in a Spanish population of the barn swallow Hirundo rustica. A comparison across age classes revealed that chewing lice load, song duration, mean peak amplitude frequency of songs, and tail length differed significantly between yearlings and adults. In a longitudinal analysis, we found significant evidence for mean peak amplitude frequency of songs, tail length and chewing louse parasitism, and a nonsignificant tendency for song duration to change with age of an individual. We found a significant association between song duration and chewing louse load and between hematocrit and peak amplitude frequency of the rattle, the typical harsh terminal syllable. In tests for associations between song traits and health status, while controlling for age, age and chewing louse load were independently related to song duration. We found a significant relationship between pairing success and song duration, implying that females may use this song trait in their choice of parasite-free males. Although the song of the barn swallow may provide information about both male age and parasite resistance, signaling of health status appears to be independent of age effects, in accordance with the theory of parasite-mediated sexual selection, suggesting that male signals can be used as reliable indicators of parasitism.

Species identiby by birdsong: discrete or additive information?

Four hypotheses of how species-identifying information is conveyed in bird song were examined. The ‘releasing’ hypothesis states that only certain acoustic components of the song are used for species identification. The ‘alerting-message’ hypothesis states that some components identify the species, while others function to gain the listener's attention. The ‘additive’ hypothesis is that different parts of the song act together in summation. A final ‘syntactical’ hypothesis recognizes that the several parts of a song contribute together to evoke a response, but that a maximal response is only evoked if the parts are presented in a particular sequence. Predictions of these hypotheses were tested by determining responses of male American redstarts, Setophaga ruticilla, to model songs played to them in their breeding territories. The initial trill of the song was sufficient by itself to evoke a full response, indicating support for the releaser hypothesis, but when terminal syllables were repeated as often as those in the trill, their effect was equally strong. Additional evidence allowed rejection of alerting-message and syntactical hypotheses. It is concluded that the evidence from redstarts favours the additive hypothesis.

Song variation in insular and mainland California Brown Creepers(Certhia familiaris)

Songs of Brown-Creepers(Certhia familiaris) in California were studied. Each individual usually sang one theme. Two geographic groups of songs were described which were designated the northern and southern dialects. These songs differed in the morphology of the introductory and terminal syllables. The northern dialect is currently known to extend from Point Reyes to the City of San Francisco, and includes birds from east San Francisco Bay. The southern dialect ranges from Carmel and Point Lobos to Morro Bay. Birds from the Hastings Reservation, 30 miles inland, sang the southern dialect. Creepers on Angel Island exhibited the “typical” island phenomenon of simpler structure but greater individual variability. We suggested that lack of social interaction due to dispersed habitat has contributed to these song changes. California Creeper songs are more variable with regard to note sequencing than those of their European congeners.

An inductive theory for free products of groups

In this paper we apply the ideas introduced in §6 of [1] to free products. While it is easy but tedious to show that the theory of a free product of two groups-not both of order two-becomes undecidable upon adjunction of a binary predicate for equality of syllable length (cf. [2]), we feel that there is hope of finding conditions for the factors that ensure decidability for the theories described below. They are based on a unary operation that picks out the terminal syllable of a word. A natural induction schema plays a crucial role and allows the development of the usual combinatorial machinery. The main purpose of this paper is the publication of some problems whose solutions should shed some new light on Tarski's conjectures.

A Rhythmic Model of English

The subjective impression that English tends to be spoken rhythmically-that is, with recurrent alternations of stronger and weaker elements-is apparently due chiefly to the rhythmic recession of accents: potentially accentable prenuclear heavy syllables tend to be realized as unaccented if flanked closely by neighboring accented syllables. Accent, though it usually augments the duration of the affected syllable, is primarily manifested by a pitch obtrusion. Despite the myth of isochronism, it takes longer to get from one accented syllable to the next if several unaccented syllables intervene, even if all are light (hence, cet, par., short), than if only one or none does. The durational factors needed, e.g., to synthesize natural-sounding speech (leaving aside such paralinguistic effects as pauses, hesitations, and abrupt changes of speech rate) are (a) inherent syllable duration, depending on phonematic makeup; syllable weight (heavy ones are longer, cet. par.); accent (accented syllables are longer, cet. par.); and location in sense group (terminal syllables are drawled). Rhythmic can be used loosely to refer to differences in any of these factors, but in the strict sense English is better described as arrhythmic.

The Term “Radian” in Trigonometry

NATURE of April 21, containing Mr. Thomson's letter, has just reached me, and I hasten to say that, had I known that his father had ever claimed to have originated the word “radian” I should, of course, have mentioned the claim in my communication to NATURE of April 7. As a matter of fact, Prof. Thomson never did so in my presence, and he certainly knew shortly after he came to Glasgow that I had on my own initiative proposed the word, and had made use of it for some years. One day when I met him accidentally he told me that he had found a college student who had been a pupil of mine using the word “radial” for a unit-angle, and that, while agreeing with me as to the need of such a word, he had doubts as to the suitability of the terminal syllable. My reply, as may be guessed from my recent communication, was that “radial”, “radian”, “rad”, had all something to be said for them, and I referred him to my letter to NATURE dated April 4, 1870. On at least two subsequent occasions we spoke of such things, and he supported the termination -an in this particular case, because of a supposed analogy with the geometrical term “median”. All this, you will see, does not preclude the possibility of an independent origination of the term by him in July, 1871, as stated by Mr. Thomson, and I therefore regret that here there is no chance of me having the satisfaction of seeing the printed word in the Calendar of Queen's College, Belfast, for 1873–4.