Gotowa bibliografia na temat „Oscines”

The difference in treatment of vocal features in Oscines and Suboscines passerine birds characterizes a large portion of the current studies on their taxonomy. In the former taxon, vocalization is supposed to be molded by learning, and consequently is not regarded as taxonomically informative. In the latter, a strong emphasis is given to vocalization because it supposedly reflects the genetic structure of populations. This paper reviews the various assumptions related to this difference in treatment, including the overestimation of the vocal characters in suboscine alpha taxonomy due to the alleged importance of vocalization under the framework of the species mate recognition system. The innate origin of suboscine vocalizations remains to be rigorously demonstrated and the use of vocalization as “super-characters” is prejudicial to bird taxonomy. Despite the possibility of being learned, vocalization should also be used in the taxonomic studies of oscine passerines. Keywords: Vocalization, Oscines, Suboscines, Birds, Passeriformes

Abstract We report the wing bones of a small passeriform bird from the early Oligocene of France, which are among the earliest fossil remains of Passeriformes in Europe. The specimen is clearly distinguished from oscines, to which all extant European passeriforms belong, and closely resembles suboscine passerines in presumably derived features. If future, more complete specimens support its assignment to the suboscines, it would be the earliest fossil record of this passeriform taxon. Together with other fossils from the early Oligocene of Germany, it indicates that nonoscine passerines colonized Europe before the arrival of oscines.

We ask whether rates of evolution in traits important for reproductive isolation vary across a latitudinal gradient, by quantifying evolutionary rates of two traits important for pre-mating isolation—avian syllable diversity and song length. We analyse over 2500 songs from 116 pairs of closely related New World passerine bird taxa to show that evolutionary rates for the two main groups of passerines—oscines and suboscines—doubled with latitude in both groups for song length. For syllable diversity, oscines (who transmit song culturally) evolved more than 20 times faster at high latitudes than in low latitudes, whereas suboscines (whose songs are innate in most species and who possess very simple song with few syllable types) show no clear latitudinal gradient in rate. Evolutionary rates in oscines and suboscines were similar at tropical latitudes for syllable complexity as well as for song length. These results suggest that evolutionary rates in traits important to reproductive isolation and speciation are influenced by latitude and have been fastest, not in the tropics where species diversity is highest, but towards the poles.

AbstractBirdsong is one of the main models in sexual selection studies. Most investigations focused on oscines in which male song and female preference learning occur. Yet, some non-oscines are well suited for such studies as well. In Columbidae song learning does not occur. However, like in oscines, song is involved in inter- and intra-sexual interactions. Surprisingly, experimental evidence of female song-based preferences are still largely lacking in this group. We conducted playback tests on wild-caught Streptopelia decaocto females. We tested for the sexual function of song by playing decaocto songs versus songs of an unrelated species. We then investigated female responses to trill. Although they do not produce this trait, males react more strongly to artificially trilled decaocto songs, i.e. to conspecific songs in which a trill from a S. roseogrisea song has been inserted, than to normal decaocto songs. We also tested female responses to S. roseogrisea songs. Females flew more often and with a shorter latency during decaocto songs than during wren songs, suggesting that species recognition occurred, but we found no evidence of preference for trilled decaocto songs. The low activity observed during the experiment might have obscured actual preferences. Nevertheless, females consistently reacted more to normal decaocto songs than to trilled decaocto or roseogrisea songs. This contrasts with the strong responses for trilled decaocto songs and the virtual lack of reaction to S. roseogrisea songs observed in males. Thus, female collared doves, as receivers, may have different characteristics from males and impose constraints on the evolution of song.

Abstract Songbirds (Passeriformes) occur in the fossil record of the Northern Hemisphere around the early Oligocene. It has recently been suggested that the major passeriform lineages diverged in Gondwana in the mid- to late Cretaceous and that the oscines, which include all extant European songbirds, originated on the Australian continental plate. Suboscines are assumed to have originated in western Gondwana. Although there is an abundant fossil record of songbirds in Europe, few attempts have been made to set those remains in a phylogenetic context. Our examination of fossil songbirds from three middle Miocene localities in Germany and France shows that many lack the derived morphology of the hypotarsus that characterizes extant Eupasseres (a taxon that comprises oscines and suboscines). We assume that these fossil taxa are outside the crown-group of Eupasseres, which indicates the presence of an ancient songbird avifauna in the Miocene of Europe, in addition to the few fossil Eupasseres already described in the literature.

The feather mite genus Trouessartia (Analgoidea: Trouessartiidae), with 145 known species, is the second most species-rich genus of feather mites. Species of Trouessartia are mostly associated with passerines (oscines and suboscines), with a few associations with woodpeckers. On hosts, the mites inhabit flight feathers, most commonly occurring on the secondaries and rectrices.

The group known as the new world nine-primaried oscines is a large and diverse group containing about 10% of the living species of birds. The group is poorly known karyologically and phylogenetic relationships of some species within the group remain uncertain. In this paper, karyological data relating to the relationships of three species are presented. The data is also useful for exploring the nature of chromosomal evolution in birds. Two species of Parulinae were studied, with other warblers for comparison. Karyological data strongly supported removal of the Olive Warbler, Peucedramus taeniatus, from Parulinae. The Yellow-breasted Chat, Icteria virens, was found to be aberrant but properly a member of Parulinae. The genus Dendroica was found karyotypically conservative, with no differences between four species. The genus Vermivora was distinguished from other genera by large blocks of heterochromatin at the centromeres of most macrochromosomes. It appears that the Five-striped Sparrow, Amphispiza quinquestriata, is properly placed in its genus according to analysis of a data set that combined karyological and morphological data. This work strongly suggests that Chromosomal evolution is decoupled from the speciation process in Emberizidae. More intrageneric karyotypic variation was found within Emberizinae than has been previously reported from any bird taxon. There was a great deal of karyotypic rearrangement between species in Thraupinae and Cardinalinae. The rearrangements appear to be due to pericentric inversion. The heteromorphisms in the karyotypes of A. quinquestriata and Pipilo erythrophthalmus when combined with reports of heteromorphisms in other nine-primaried oscine species suggest this group has mechanisms to avoid meiotic irregularities usually associated with pericentric inversion. Further karyological studies of the nine-primaried oscines are required to improve our understanding of chromosomal evolution in the group.

A presente Dissertação apresenta dados sobre dois estudos complementares: a filogenia do gênero Paroaria (Aves: Passeriformes: Oscines; Capítulo 2) e a filogeografia de Paroaria dominicana (Capítulo 3). O estudo filogenético do gênero Paroaria utilizou como fonte de dados seqüências do ND2 (1041 pb) obtidas a partir de indivíduos das cinco espécies desse gênero (exceto P. baeri com 925 pb) e de seis espécies de diferentes tribos da subfamília Emberizinae como grupos externos. As reconstruções filogenéticas obtidas indicam que: 1) táxons da atual tribo Emberizini não formam um grupo monofilético; 2) Gubernatrix cristata pertence à tribo Thraupini; 3) dentre as espécies amostradas, G. cristata é a mais próxima ao gênero Paroaria; 4) o gênero Paroaria é monofilético; 5) o gênero Paroaria está dividido em dois clados principais: (P. coronata, P. dominicana) e (P. baeri (P. gularis, P. capitata)). Para auxiliar a interpretação dos resultados, as distribuições dos registros das espécies do gênero Paroaria foram obtidas por meio da compilação de informações de localidades de coleta de onze instituições. O clado (P. coronata, P. dominicana) sugere que as florestas abertas dos arredores do Chaco e da Caatinga estão relacionadas. Já o clado (P. baeri (P. gularis, P. capitata)) sugere relação entre as matas ciliares do Cerrado, da Amazônia, do Pantanal e dos arredores do Chaco. Estimativas de datas de divergências sugerem que as diversificações mais antigas dentro do gênero Paroaria ocorreram no período Plioceno, enquanto apenas a mais recente ocorreu no Pleistoceno inferior. Eventos paleogeográficos e paleoclimáticos poderiam estar associados às diversificações. Já o estudo filogeográfico da espécie P. dominicana utilizou como fonte de dados seqüências do ND3 (351 pb) e do primeiro domínio da região controladora (391 pb) obtidas a partir de 51 indivíduos dessa espécie. A espécie irmã P. coronata foi selecionada como grupo externo. Porém, devido a problemas laboratoriais ela foi substituída por P. capitata em algumas matrizes. Testes de neutralidade foram aplicados aos dados e sugerem que: 1) há fuga do modelo de populações em equilíbrio neutro causada por seleção positiva (fase pré ou pós-fixação) ou seleção negativa atuando concomitantemente ou não a uma expansão populacional recente; e 2) a não utilização do grupo externo mais adequado causou saturação nos dados, prejudicando a realização de inferências mais precisas sobre as forças causadoras do padrão de polimorfismos encontrado. Com isso, análises de demografia histórica e de tamanho populacional efetivo foram comprometidas. As análises de estrutura populacional indicam que: 1) a espécie P. dominicana não apresenta estruturação populacional para o DNAmt; 2) essa espécie deve ser tratada como uma única Unidade de Manejo; e 3) o rio São Francisco e os tipos de Caatinga não constituem barreiras geográfica e ecológica para essa espécie, respectivamente.
This Masters Thesis comprises two complementary studies: phylogeny of the genus Paroaria (Aves: Passeriformes; Oscines; Chapter 2) and phylogeography of Paroaria dominicana (Chapter 3). The phylogeny of the genus Paroaria is based on complete ND2 (1041 bp) sequences from all five Paroaria species (except P. baeri with 925 bp) and from six species from different tribes of the subfamily Emberizini as outgroups. The results indicate that: 1) the current tribe Emberizini is not monophyletic; 2) Gubernatrix cristata should be placed within the tribe Thraupini; 3) among the outgroups sampled, G. cristata is the closest to genus Paroaria; 4) genus Paroaria is monophyletic; and 5) genus Paroaria is comprised of two major clades: (P. dominicana, P. coronata) and (P. baeri (P. gularis, P. capitata)). To help interpreting the results, the distribution of sampling localities of the genus Paroaria was compiled from eleven institutions. The clade (P. dominicana, P. coronata) indicates an association between the open forests of Caatinga and around the Chaco. The clade (P. baeri (P. gularis, P. capitata)) suggests that the riparian forests of Cerrado, Amazon, Pantanal and around the Chaco are related. Date estimates of diversification indicate that the oldest splits within the genus occurred during the Pliocene, and only the youngest diversification occurred during the early Pleistocene. Paleogeographic and paleoclimate events could be related to these diversifications. The phylogeography of the species P. dominicana is based on sequences from of ND3 (351 bp) and first domain of the control region (391 bp) from 51 individuals. The sister species P. coronata was used as outgroup. However, due to technical problems it was replaced by P. capitata in some data matrices. Neutrality tests results suggest that: 1) there is departure from the neutral equilibrium population model due to negative or positive selection (pre or post fixation phases) acting simultaneously or not with a recent population expansion; and 2) the use of a non-sister outgroup caused saturation of the data, jeopardizing more precise inferences on the forces shaping the polymorphism pattern found. Therefore, historical demography and effective population size analyses could not be performed. The population structure analyses suggest that: 1) the species P. dominicana is not geographically structured based on mtDNA data; 2) this species can be considered as a single Management Unit; and 3) the São Francisco river and the types of Caatinga are not geographic and ecological barriers for this species, respectively.

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CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Sabe-se que as regiões cerebrais envolvidas no controle do canto são sexualmente dimórficas em muitas espécies de pássaros adultos de regiões temperadas como nos zebra finches em que os machos cantam e as fêmeas não cantam. Em diversas espécies de pássaros canoros dos trópicos, contudo, tanto os machos quanto as fêmeas são capazes de cantar. Porém, os mecanismos envolvidos na produção do canto em fêmeas ainda é pouco compreendido. Com o intuito de identificar diferenças que possam explicar o canto em fêmeas, nós estudamos a morfologia do sistema do canto de pássaros machos e fêmeas da espécies Uraegynthus cyanocephalus, espécie esta em que tanto machos quanto fêmeas cantam. Como primeiro passo para a análise e estabelecimento de diferenças anatômicas quanto ao sexo, nós quantificamos alterações de volume de áreas prosencefálicas relacionadas ao cantos, através de marcação com Nissl e de marcação de receptores andrógenos (RA) por meio de hibridização in situ radioativa. Nós verificamos que, tanto em machos quanto em fêmeas, o volume do centro vocal superior (HVC) não sofre alteração estatisticamente significativa ao longo do desenvolvimento. Observamos, ainda, que o volume do HVC em machos é sempre superior ao das fêmeas, inclusive na fase adulta, quando esta diferença se torna significativa, existindo portanto, dimorfismo sexual. Contrariamente ao desenvolvimento do HVC, o núcleo robusto do arcopalio (RA) de machos aumenta de modo significativo gradualmente com a idade, atingindo o seu pico de crescimento na fase adulta. O volume do RA aumentou em 2,21 vezes no macho (0,104 mm3 em 20 dias para 0,236 mm3 na idade adulta). Nas fêmeas, as alterações volumétricas de RA observadas ao longo do crescimento não foram significativas.
Song control regions in passerine birds are sexually dimorphic in the adult brain of species like the zebra finches in which males sing whereas females do not. In the majority of tropical bird species, however, females sing as well. The issue of female song production began to attract more attention recently, but the neural mechanisms involved in the female song production are still poorly understood. Here we study for the first time the ontogeny of the song control system in a species, in which both male and female sing regularly. In blue-capped cordon blues (Uraeginthus cyanocephalus), a close relative of the zebra finch, females sing but have shorter songs with fewer syllables compared to the males. Volumetric changes of forebrain song control regions (the HVC, the RA and the LMAN) of the blue capped cordon bleu have been quantified in both sexes at 20, 30, 50 and ≥100 days posthatching, by using the Nissl- taining method and in situs hybridization. In both sexes, no significant differences in the volumetric development of HVC (proper name) were detected. The Nissl-efined volume of the HVC in males was always superior to the females values, including the adulthood, when the volume values became significant bigger in males than in females. In contrast, the volume of the robust nucleus of the archistriatum (RA) increased with age reaching the highest values in adulthood. The Nissl-defined RA volume incresed by 2,21 times in males (from 0,104 mm3 at 20 days to 0,236 mm3 in adulthood). In females, no significant differences in the volumetric development of RA were detected.

An undue focus on Temperate Zone oscines (songbirds or passerines) has led to a geographical bias in interpretation of song frmnction and evolution. This bias led initially to relatively simplistic theories of the ftmnction of bird song with vocalizations divided into 'songs' and 'calls'. Songs were complex, learned vocalizations, given by males in the breeding season, thnctioning in territory defence and mate attraction and stimulation. Calls, on the other hand, were simple innate vocalizations serving more immediate needs such as begging for food and raising an alarm. Female song, where it occurred, was considered an aberration. Further studies suggested that complex songs were associated with mate attraction functions while simpler songs were associated with territory defence. However it became apparent that the distinction between songs and calls was not nearly so clear-cut and the supposed connection between complexity and function in song was questioned. Moreover it was realised that female song could not be dismissed as a mere aberration. Another problem was the ftmnction of the dawn chorus, where research had failed to find a consistent, all-encompassing explanation. Since most studies had been done on Northern Hemisphere songbirds, it was becoming clear that the geographical focus needed to be broadened. The life histories of Northern Hemisphere TemperateZone songbirds are very different from those in many other regions. In contrast to the situation in this zone, maintenance of year-round territory, territory defence by both male and female, life-long social monogamy and extensive female vocalization are widespread in tropical, subtropical and Southern Hemisphere regions. Recently it has been suggested that more intensive studies of vocalizations in these regions might help clariQi some of these issues and consequently an endemic Australian passerine was chosen for the current study. The study focused on the vocalizationsof the grey butcherbird Cracticus torquatus Artamidae, which displays the life history features described above. The main study population was located in the Brisbane suburbs of Rainworth and Bardon. Additional data were gathered from other Brisbane suburbs and bushland sites within the city and at Lake Broadwater near Dalby, Queensland. Vocalizations were initially recorded electronically and analysed using Canary sound editing program. Vocalization data were supplemented using an aural recording method, which was independently checked for reliability. Behavioural data including posture during vocalizations and interactions with other birds were also gathered. Initial investigationsrevealed the existence of two main categories of vocalizations - those given by the family group during the day, all year round and those given at dawn by males during the breeding season. For the focal study populations, group vocalizations were studied throughout the year over several years, however the song given at dawn by males during the breeding season proved to be quite complex and three birds from three territories in the main study area were chosen as case studies. Recordings were made of the vocalizations of the three case study birds over three breeding seasons. Starting and fmishing times (with respect to civil twilight) were recorded in order to determine both changes in song bout duration and starting time throughout the breeding season. Additional birds from the same area, from the other Brisbane suburbs and from the bushland sites were studied to check the validity of conclusions drawn from the case studies. The results of the investigations revealed a vocalization structure that contrasted strongly with the simple picture of bird song drawn from study ofNorthernHemisphere Temperate Zone passerines. The vocalizations given during the day, often referred to as the 'song' of this species, were very different from the early dawn song given by the male during the breeding season. This latter appeared to be song sensu stricto according to the paradigms developed for Northern Hemisphere birds. The thytime vocalizations, however, fitted neither the classic definition of 'song' nor the classic definition of 'call'. This relatively long-term study revealed different starting time patterns and periodicity for thy vocalizations and male breeding season song. Day vocalizations commenced at a fairly constant time with respect to civil twilight throughoutthe year but breeding season song started progressively earlier from the beginning through to the middle of the season then progressively later till the end of the season. Relative finishing time of breeding song however remained constant so that the duration of breeding season song gradually increased then decreased paralleling the change in starting times. A consequence of the two distinct classes of vocalizations was that there were essentially two distinct 'dawn choruses'. One, consisting of group vocals, was sung all year round; the other was given by males singing 'breeding season' song. Since there was no reason the expect that a single function would necessarily be ascribed to both choruses, this raised the possibility that some of the confusion surrounding the ftinction and nature of the 'dawn chorus' originated from a failure to recognize the existence of two such choruses. Variation in time and space showed ifirther differences between the two vocalization classes. The breeding song of each male was distinctly different from that of his neighbours and there was a marked change in the repertoire of any individual from one year to the next. In marked contrast, daytime vocalization repertoires of neighbouring groups were virtually indistinguishable and changed little from year to year. These findings, together with information from recent literature, suggested that the two song classes had a different ontogeny, function and possibly evolution. It was proposed that territory declaration was the function of dawn singing by grey butcherbird family groups but that the function most consistent with adult male dawn song was attraction of females for extra-pair copulations. It was suggested that chorusing itself was to some extent an accidental by-product of the advantage to the individual or group of singing at dawn although a recently proposed function, the social dynamics function, could not be ruled out. Further differences from the Northern Hemisphere situation were detected in subsong. First, subsong was given by birds in their first year and also by adult males. The finding of subsong in adult males was not without precedent as it has been documented previously for a small number of passerines, especially those that change repertoire from year to year. Subsong in young (first year) birds, however, was unusual in that birds practised in small groups rather than in the complete isolation usually associated with subsong. Moreover they did not practise adult male song but instead practised group daytime vocalizations. It was suggested that it was important for birds to learn to sing in company for the important task of group territory defence. Further investigation of the literature and observations during the present study revealed similar vocalization classes and behaviours in other members of the Artamidae and other endemic Australasian taxa. These literature investigations also revealed that the possession two song vocalization classes was quite widespread although they tended to be restricted (but not exclusive) to males rather than found in males and females. These findings led to furtherresearch into the significanceofAustraliain the evolution of songbirds, the role of co-operative breeding in Australianpasserines, and finally to an hypothesis for a possible origin of male bird song. It is suggested that male song arose in a social environment where the male and female were in frequent vocal communication. If the tendency to seek extra-pair copulations (EPCs) and female choice had already been incorporated into the suite of passerine behaviours, it would be necessary to avoid the mate during such activities and the male would need to advertise with a signal distinct from group vocalizations. Early dawn, with poor light conditions, could be a favourable time for these activities. Thus it is proposed that the ancestral condition was with all group members singing most vocalisations, the intermediate situation was similar to that in the grey butcherbird and the 'advanced' condition was where female and other group member vocalizations (other than calls) have dropped out and only male song remains.

A l’heure actuelle, il reste largement à étudier comment le codage sensoriel des signaux vocaux de communication contribue à leur détection et à leur reconnaissance. Peu d’études se sont, en effet, penchées sur le codage des vocalisations au niveau des régions auditives en fonction de l’individu qui les produit et du degré de familiarité avec cet individu. Dans ce cadre, les oiseaux chanteurs sont un bon modèle parce qu’ils utilisent des vocalisations pour interagir et reconnaître leurs congénères et qu’ils possèdent, de plus, un ensemble de régions auditives. Parmi ces régions, le nidopallium caudomedian (NCM), une aire auditive analogue du cortex auditif secondaire chez les mammifères, est actuellement considérée comme une région spécialisée dans le traitement des vocalisations (chants et cris) de l’espèce : les neurones du NCM répondent plus fortement aux vocalisations de l’espèce qu’à celles d’une autre espèce. À partir de là, parce que chez le diamant mandarin, le cri de distance permet aux individus, mâles ou femelles, de reconnaître leur partenaire sexuel, nous avons cherché à savoir si, chez les femelles comme chez les mâles, les neurones du NCM montraient une discrimination dans leurs réponses auditives entre le cri d’individus connus (parmi lesquels figurait le partenaire sexuel) et ceux d’individus inconnus et si ces réponses reflétaient le degré de familiarité de ces vocalisations. Les enregistrements de l’activité des neurones du NCM, chez des diamants mandarins vigiles (grâce à un système de télémétrie) ou anesthésiés, lors de la présentation de cris de distance, ont révélé, chez les femelles vivant en couple et ayant été familiarisées avec un autre couple de diamants mandarins, une plus forte augmentation de l’activité lors de la diffusion des cris d’individus connus, mâles ou femelles, qu’aux cris d’individus inconnus. Une telle augmentation n’a pas été, en outre, observée chez des femelles contrôles qui n’avaient jamais entendu ces mêmes cris auparavant. De plus, ils ont indiqué que le nombre de neurones montrant un fort degré de sélectivité ainsi que la quantité d’information portée par les trains de potentiels d’action étaient plus importants chez les femelles vivant en couple que chez les femelles contrôles. En revanche, chez les mâles, bien que la plupart des neurones montrait des réponses lors de la diffusion des cris, aucune différence n’a été mise en évidence entre les cris d’individus connus et ceux d’inconnus. Nous avons alors cherché à savoir comment, d’un point de vue acoustique, les cris de distance étaient représentés au sein du NCM. En se basant sur une étude comportementale ayant déterminé quelles étaient les caractéristiques acoustiques qui contribuaient à la reconnaissance de ces cris, nous avons cherché à savoir si les neurones du NCM étaient sensibles à ces mêmes caractéristiques acoustiques. Les résultats ont montré que, chez les femelles, la suppression de la fréquence fondamentale et la modification du timbre du cri du partenaire sexuel ou du propre cri de l’oiseau provoquaient une forte diminution des réponses au sein du NCM alors que, chez les mâles, les réponses variaient selon le paramètre modifié et le type de cri présenté. Nos résultats suggèrent donc que, chez le diamant mandarin, le NCM est impliqué dans le codage du cri de distance. Cependant, ils mettent en évidence des différences dans ce codage entre les mâles et les femelles. Chez les femelles, ce codage permet de discriminer entre les cris d’individus connus et ceux d’individus inconnus alors que chez les mâles, son rôle reste à être déterminé. Chez les femelles, l’expérience sociale au travers de la mémorisation des signaux de communication des individus peut donc façonner les propriétés fonctionnelles des neurones d’une aire auditive secondaire. Ces propriétés pourraient donc continuellement subir des changements pour s'adapter à l’environnement social de l’individu
How sensory signals are encoded in the brain and whether their behavioural relevance affects their encoding are central questions in sensory neuroscience. Studies have consistently shown that behavioural relevance can change the neural representation of sounds in the auditory system, but what occurs in the context of natural acoustic communication where significance could be acquired through social interaction remains to be explored. The zebra finch, a highly social songbird species that forms lifelong pair bonds and uses a vocalization, the distance call, to identify its mate offers an opportunity to address this issue. One auditory area in the songbird telencephalon, the caudo-medial nidopallium (NCM) that is considered as being analogous to the secondary mammalian auditory cortex, has recently emerged as part of the neural substrate for sensory representation of species-specific vocalizations: the activation of NCM neurons is greatest when birds are exposed to conspecific song, as compared to heterospecific song or artificial stimuli. This led us to investigate whether, in the zebra finch, NCM neurons could contribute to the discrimination among vocalizations that differ in their degree of familiarity: calls produced by the mate, by familiar individuals (males or females), or by unfamiliar individuals (males or females). In females, behaviourally relevant calls, i.e. the mate’s call and familiar calls, evoked responses of greater magnitude than unfamiliar calls. This distinction between responses was seen both in multiunit recordings from awake freely moving mated females (using a telemetric system) and in single unit recordings from anesthetized mated females. In contrast, control females that had not heard them previously displayed response of similar magnitude to call stimuli. In addition, more cells showed highly selective responses in mated than in control females suggesting that experience-dependent plasticity in call-evoked responses resulted in enhanced discrimination of auditory stimuli. In males, as in females, call playback evoked robust auditory responses. However, neurons in males did not appear capable of categorizing the calls of individuals (males or females) as ‘‘familiar’’ or ‘‘unfamiliar’’. Then, we investigated how calls are represented in the NCM of zebra finches by assessing whether certain call-specific acoustic cues drove NCM neurons to a greater degree than others. Behavioural studies had previously identified call-specific acoustic cues that are necessary to elicit a vocal response from male and female zebra finches. Single-unit recordings indicated that NCM neurons in females were particularly sensitive to call modifications in the spectral domain: suppressing the fundamental frequency of call stimuli or modifying the relative energy levels of harmonics in call caused a marked decrease in response magnitude of NCM neurons. In males, NCM neurons also appear to be sensitive to call modifications in the spectral domain, however changes in magnitude of responses (increase or decrease) depended on the acoustic cue that had been modified.Our results provide evidence that the NCM is a telencephalic auditory region that contributes to the processing of the distance call, in females as well in males. However, how the distance call is processed and represented in the NCM appears to differ between males and females. In females, the NCM could be involved in dicrimination between call stimuli whereas, in males, its functional role in call-processing remains to be determined. Our results also suggest that, in females, social experience with the call of individuals, by affecting the degree to which neurons discriminated between these calls, may shape the functional properties of neurons in a telencephalic auditory area. The functional properties of auditory neurons may therefore change continuously to adapt to the social environment

Pendant la première période de leur vie, les bébés et les jeunes oiseaux présentent des phases de développement vocal comparables : ils écoutent d'abord leurs parents/tuteurs afin de construire une représentation neurale du stimulus auditif perçu, puis ils commencent à produire des sons qui se rapprochent progressivement du chant de leur tuteur. Cette phase d'apprentissage est appelée la phase sensorimotrice et se caractérise par la présence de babillage. Elle se termine lorsque le chant se cristallise, c'est-à-dire lorsqu'il devient semblable à celui produit par les adultes.Il y a des similitudes entre les voies cérébrales responsables de l'apprentissage sensorimoteur chez l'homme et chez les oiseaux. Dans les deux cas, une voie s’occupe de la production vocale et implique des projections directes des zones auditives vers les zones motrices, et une autre voie s’occupe de l’apprentissage vocal, de l'imitation et de la plasticité.Chez les oiseaux, ces circuits cérébraux sont exclusivement dédiés à l'apprentissage du chant, ce qui en fait un modèle idéal pour explorer les mécanismes neuronaux de l’apprentissage vocal par imitation.Cette thèse vise à construire un modèle de l'apprentissage du chant des oiseaux par imitation. De nombreuses études antérieures ont tenté de mettre en œuvre l'apprentissage par imitation dans des modèles informatiques et partagent une structure commune. Ces modèles comprennent des mécanismes d'apprentissage et, éventuellement, des stratégies d'exploration et d'évaluation.Dans ces modèles, une fonction de contrôle moteur permet la production de sons et une réponse sensorielle modélise soit la façon dont le son est perçu, soit la façon dont il façonne la récompense. Les entrées et les sorties de ces fonctions sont dans plusieurs espaces: l'espace moteur (paramètres moteurs), l'espace sensoriel (sons réels), l'espace perceptif (représentation à faible dimension du son) ou l’espace des objectifs (représentation non perceptive du son cible).Le premier modèle proposé est un modèle théorique inverse basé sur un modèle d'apprentissage vocal simplifié où l'espace sensoriel coïncide avec l'espace moteur (c'est-à-dire qu'il n'y a pas de production sonore). Une telle simplification permet d'étudier comment introduire des hypothèses biologiques (par exemple, une réponse non linéaire) dans un modèle d'apprentissage vocal et quels sont les paramètres qui influencent le plus la puissance de calcul du modèle.Afin de disposer d'un modèle complet (capable de percevoir et de produire des sons), nous avions besoin d'une fonction de contrôle moteur capable de reproduire des sons similaires à des données réelles. Nous avons analysé la capacité de WaveGAN (un réseau de génération) à produire des chants de canari réalistes. Dans ce modèle, l'espace d'entrée devient l'espace latent après l'entraînement et permet la représentation d'un ensemble de données à haute dimension dans une variété à plus basse dimension. Nous avons obtenu des chants de canari réalistes en utilisant seulement trois dimensions pour l'espace latent. Des analyses quantitatives et qualitatives démontrent les capacités d'interpolation du modèle, ce qui suggère que le modèle peut être utilisé comme fonction motrice dans un modèle d'apprentissage vocal.La deuxième version du modèle est un modèle d'apprentissage vocal complet avec une boucle action-perception complète (il comprend l'espace moteur, l'espace sensoriel et l'espace perceptif). La production sonore est réalisée par le générateur GAN obtenu précédemment. Un réseau neuronal récurrent classant les syllabes sert de réponse sensorielle perceptive. La correspondance entre l'espace perceptuel et l'espace moteur est apprise par un modèle inverse. Les résultats préliminaires montrent l'impact du taux d'apprentissage lorsque différentes fonctions de réponse sensorielle sont mises en œuvre
During the first period of their life, babies and juvenile birds show comparable phases of vocal development: first, they listen to their parents/tutors in order to build a neural representation of the experienced auditory stimulus, then they start to produce sound and progressively get closer to reproducing their tutor song. This phase of learning is called the sensorimotor phase and is characterized by the presence of babbling, in babies, and subsong, in birds. It ends when the song crystallizes and becomes similar to the one produced by the adults.It is possible to find analogies between brain pathways responsible for sensorimotor learning in humans and birds: a vocal production pathway involves direct projections from auditory areas to motor neurons, and a vocal learning pathway is responsible for imitation and plasticity. The behavioral studies and the neuroanatomical structure of the vocal control circuit in humans and birds provide the basis for bio-inspired models of vocal learning.In particular, birds have brain circuits exclusively dedicated to song learning, making them an ideal model for exploring the representation of vocal learning by imitation of tutors.This thesis aims to build a vocal learning model underlying song learning in birds. An extensive review of the existing literature is discussed in the thesis: many previous studies have attempted to implement imitative learning in computational models and share a common structure. These learning architectures include the learning mechanisms and, eventually, exploration and evaluation strategies. A motor control function enables sound production and sensory response models either how sound is perceived or how it shapes the reward. The inputs and outputs of these functions lie (1)~in the motor space (motor parameters’ space), (2)~in the sensory space (real sounds) and (3)~either in the perceptual space (a low dimensional representation of the sound) or in the internal representation of goals (a non-perceptual representation of the target sound).The first model proposed in this thesis is a theoretical inverse model based on a simplified vocal learning model where the sensory space coincides with the motor space (i.e., there is no sound production). Such a simplification allows us to investigate how to introduce biological assumptions (e.g. non-linearity response) into a vocal learning model and which parameters influence the computational power of the model the most. The influence of the sharpness of auditory selectivity and the motor dimension are discussed.To have a complete model (which is able to perceive and produce sound), we needed a motor control function capable of reproducing sounds similar to real data (e.g. recordings of adult canaries). We analyzed the capability of WaveGAN (a Generative Adversarial Network) to provide a generator model able to produce realistic canary songs. In this generator model, the input space becomes the latent space after training and allows the representation of a high-dimensional dataset in a lower-dimensional manifold. We obtained realistic canary sounds using only three dimensions for the latent space. Among other results, quantitative and qualitative analyses demonstrate the interpolation abilities of the model, which suggests that the generator model we studied can be used as a motor function in a vocal learning model.The second version of the sensorimotor model is a complete vocal learning model with a full action-perception loop (i.e., it includes motor space, sensory space, and perceptual space). The sound production is performed by the GAN generator previously obtained. A recurrent neural network classifying syllables serves as the perceptual sensory response. Similar to the first model, the mapping between the perceptual space and the motor space is learned via an inverse model. Preliminary results show the influence of the learning rate when different sensory response functions are implemented

L’objectif de la thèse a été d’étudier la structure, la fonction et la plasticité au cours du temps du chant d’un oiseau mâle adulte, la fauvette à tête noire Sylvia atricapilla. L’influence de différents comportements migratoires sur les caractéristiques du chant, sur la maintenance des dialectes et sur l’apprentissage a également été étudiée chez deux populations, une migratrice (représentée par 2 groupes à Paris) et une sédentaire (représentée par 3 groupes en Corse). Le chant de cette espèce est constitué de deux parties aux caractéristiques acoustiques bien distinctes, le warble et le whistle. Nos expériences de diffusion montrent que chacune des deux parties peut provoquer une réponse territoriale des mâles. Ce chant en deux parties permet probablement aux fauvettes de transmettre des informations différentes, destinées à différents auditoires, proches et lointains, mâles et femelles. Nos analyses génétiques par microsatellites ne montrent pas de structure génétique des groupes et populations. Néanmoins, nous avons montré l’existence de variations micro-géographiques au niveau de la composition en syllabes et en séquences de syllabes de cette seconde partie du chant. Bien que le renouvellement des individus soit plus important chez les migrateurs que chez les sédentaires, les 2 populations ont un taux de partage de syllabes et de phrases équivalent au sein des groupes. Nous avons cependant observé que les individus migrateurs ont un répertoire de syllabes 2 fois plus grand mais une diversité de phrases partagées 2 fois moins grandes que les sédentaires. Le suivi d’individus sédentaires sur plusieurs années consécutives a permis de montrer que l’espèce faisait preuve d’une plasticité vocale puisqu’on observe un plus grand partage de syllabes et de phrases intra année qu’inter année au sein des groupes. Même si les individus semblent modifier le contenu de leurs chants chaque année, nous n’avons pas réussi à mettre en évidence par des expériences de diffusion en milieu naturel un apprentissage à l’âge adulte de nouvelles syllabes ou de nouvelles phrases
The aim of the thesis was to study the structure, function and plasticity over time of the song of a male adult bird, the blackcap Sylvia atricapilla. The influence of different migratory behaviors on the song characteristics, on the dialect maintenance and on learning has also been studied in two populations, a migratory one (represented by two groups in Paris) and a sedentary one (represented by 3 groups in Corsica). The song of this species consists of two parts with distinct sound characteristics, the warble and the whistle. Our playback experiments show that both parts trigger male territorial response. Such a song in two parts probably allows blackcaps to transmit different information for different audiences, close and distant, males and females. Genetic analyzes with microsatellites show no genetic structure of groups and populations. Nevertheless, we have shown the existence of micro-geographical variations in the composition of syllables and sequences of syllables in the whistle part. Although the turnover of individuals is higher among migrants than among sedentary populations, the two populations have similar syllables and phrases sharing within groups. However, migratory birds, compared to sedentary ones, have a syllable repertoire size twice as large and a repertoire of phrase sharing much smaller. The survey of sedentary individuals over several consecutive years has shown that the species show a vocal plasticity since a greater sharing of syllables and of phrases is observed intra year than between years within groups. Although individuals seem able to modify their songs every year, we didn’t succeed in showing with playback experiments in natural environment that adults males were able to learn new syllables or new phrases

O ruído antropogênico pode afetar a comunicação acústica das espécies através do mascaramento, com possíveis efeitos sobre o valor adaptativo. Assim, diversas espécies de grupos distintos apresentam diferenças em características de suas vocalizações ou em seu comportamento entre locais mais e menos ruidosos, permitindo-as sobreviver e reproduzir nos locais com mais ruído. As diferenças podem surgir por mudanças de curto (plasticidade vocal), médio (ontogênese) ou longo prazo (evolução). Para os mecanismos de curto e médio prazos, características intrínsecas das espécies podem interferir no processo, particularmente a forma pela qual ocorre o aprendizado. Dentro da ordem Passeriformes, os oscines apresentam aprendizado vocal, enquanto os suboscines não. Neste trabalho relatamos um estudo comparando as características das vocalizações de um oscine (corruíra, Troglodytes musculus) e um suboscine (bem-te-vi, Pitangus sulphuratus) de uma mesma população de cada espécie em dois locais de seu habitat com níveis de ruído distintos. Nós previmos que as vocalizações da corruíra apresentariam diferenças entre os locais, enquanto que as do bem-te-vi não, dadas as diferenças em plasticidade e aprendizado entre oscines e suboscines. Contrariando nossas previsões, praticamente nenhuma das características das vocalizações de ambas as espécies diferiu entre as áreas. Os resultados apontam para a possibilidade de que pode não haver adaptação acústica de curto prazo nestas espécies (ou que pode não haver diferenças entre oscines e suboscines ou aves que aprendem vs. as que não aprendem), embora haja diversas hipóteses alternativas.
Anthropogenic noise may affect acoustic communication of species through masking, with potential fitness consequences. Several species from different groups then show differences in call features or behavior between noisier and quieter regions, allowing them to survive and reproduce in the noisy places. Differences may arise through short (call plasticity), medium (ontogenetic) or long-term (evolutionary) mechanisms. For the short and medium term mechanisms, intrinsic characteristics of the species may interfere with the modification of the signals, particularly the way that vocal learning occurs. Within the Passeriform order, the oscines show vocal learning, while the suboscines do not. Here we report a study comparing song characteristics of an oscine (southern house wren Troglodytes musculus) and a suboscine bird (great kiskadee Pitangus sulphuratus) of a single population at two different places of their habitat showing different noise levels. We predicted that the oscine bird would show differences in the calls between the regions, while the suboscine species would not show them, given the differences in song learning and plasticity between those groups. Contrary to our predictions, almost none of the song parameters of both the great kiskadee and the southern house wren differed between those areas. The results point to the possibility that there might not be short term acoustic adaptation in bird song features in these species (or that there might not be a difference between oscines and suboscines or learners vs. non-learners), but several alternative hypotheses exist.

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Sócio-Econômico. Programa de Pós-Graduação em Administração.
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Este trabalho procurou conhecer as características da captação de recursos e da estrutura organizacional de Organizações da Sociedade Civil de Interesse Público (OSCIPs) ambientalistas de Florianópolis. Para isso, foi realizado um estudo de casos múltiplos com as organizações Instituto Harmonia na Terra, Aprender e Aliança Nativa. Para contextualizar o estudo, buscou-se na literatura temas como movimento ambientalista, terceiro setor, a lei das OSCIPs e a captação de recursos. Os dados foram coletados através da análise documental e entrevistas semi-estruturadas, realizadas por meio de amostragens intencionais. As análises pareceram indicar características estruturais semelhantes a organizações orgânicas, onde se destacou a descentralização e fluidez na divisão de tarefas. Observou-se que o planejamento das organizações pesquisadas ainda parece ser incipiente e realizado somente a curto ou médio prazo. As principais fontes de recursos das organizações pesquisadas são organizações públicas e privadas. Mas a opinião dos entrevistados foi a de que os resultados esperados pelos órgãos financiadores públicos e privados diferem entre si. Enquanto o órgão público espera qualidade no cumprimento do projeto proposto, o órgão privado pretende melhorar a sua imagem no mercado. Verificou-se também que as vantagens proporcionadas pela lei das OSCIPs superam suas desvantagens. Entre as vantagens relatadas estão melhorias em parcerias, a possibilidade de remunerar dirigentes e a melhoria na imagem da organização.

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Este trabalho teve como objetivo estudar as práticas de microcrédito orientado desempenhadas por Organizações da Sociedade Civil de Interesse Público (OSCIP s) no estado de Pernambuco. Nesta perspectiva, o Centro de apoio ao pequeno empreendedores do Estado de Pernambuco foi escolhido como objeto de estudo. A escolha dessa instituição se deu pelo tempo de atuação que a mesma tem no mercado e pela cobertura territorial de ação que se define em quase todo o Estado. Foram selecionados como pontos de atendimento a serem estudados as unidades do Ceape-PE em Recife, Caruaru, Santa Cruz do Capibaribe e Toritama, no período de janeiro de 2005 a julho de 2010. Tais cidades se destacam no cenário econômico de Pernambuco, o que orientou a suposição de que a representação amostral estaria adequada. O estudo procurou ainda identificar: a. se, durante o período acima indicado, ocorreu o empoderamento econômico, pessoal e político dos tomadores de empréstimo; b. se existiram diferenças entre os níveis dessas formas de empoderamento na Capital e nas cidades do Agreste e c. se a localização da OSCIP estudada (na capital e no interior) está ligada à existência de arranjos produtivos locais que fomentem a demanda por microcrédito orientado. Desta maneira, a construção do trabalho permeou o seguinte problema de pesquisa: a OSCIP de microcrédito estudada pôde trazer contribuições para o empoderamento dos seus beneficiados no Recife e no Pólo de confecções do Agreste, durante o período de janeiro de 2005 a julho de 2010? Em termos metodológicos optouse por: realizar uma entrevista com cada gestor e vinte e cinco entrevistas com beneficiários. Ao mesmo tempo, buscou-se, em linhas gerais, colaborar com os estudos sobre o Terceiro Setor em Pernambuco, identificando as contribuições que podem se trazidas à sociedade através das atividades desenvolvidas pelas instituições que o compõem