Navegando por Assunto "Som produzido por animais"

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Acesso aberto (Open Access)
Estrutura e organização de sistemas complexos de comportamento vocal em cinco espécies do Gênero Turdus (Aves, Passeriformes, Turdinae)
(Universidade Federal do Pará, 2012-03-07) NASCIMENTO, Luis Fernando Teixeira; SILVA, Maria Luisa da; http://lattes.cnpq.br/2101884291102108
Communication is essential for animal life maintenance. In birds prevails acoustic communication, the song is the sound emission that has the specific recognition function, can be repetitive and predictable or complex with variations levels between individuals conspecifics. The genus Turdus provides members with a melodious and varied song, as is the case of five syntopic species in Brazil (T. leucomelas, T. rufiventris, T. fumigatus, T. amaurochalinus and T. albicollis), the high variation level may to cause recognition confusion of these species among experienced researchers and lovers in the listening birds practice. The structure analysis and complex organization of communication systems can give us answers to their functionality. In present study we gathered recordings of 72 individuals of five species above mentioned, from various localities, identified and named each of the 4826 notes, the song units of sound, and we measure their physical parameters. Through mathematical tools based on the theory of information verified the individual predictability of the corner and use as a criterion for comparison between individuals and species. We analyzed the data, sketched sequences and synthesized the results of cluster analysis to define the structure and organization of the song. The analyzes showed similarity in the song complexity of species compared some specific patterns were observed, such as T. amaurochalinus showed the highest values of the rhythm of the song and the maximum frequency of the notes, T. albicollis stood out by low values of these parameters, as for T. leucomelas, T. rufiventris and T. fumigatus was not observed characteristics, the three species show great variation in the parameters analyzed. But the evolutionary success of these species makes it clear that their songs are successful to exercise the functions of communication and specific recognition.
Acesso aberto (Open Access)
Estudo comportamental de Besourão-de-rabo-branco Phaethornis superciliosus (Aves, Trochilidae) no Parque Ecológico de Gunma
(Universidade Federal do Pará, 2012-03-05) BRITO, Duan da Silva; SILVA, Maria Luisa da; http://lattes.cnpq.br/2101884291102108
Acoustic communication in hummingbirds has long been neglected due to the conspicuous coloration that represents a sophisticated visual communication of most representatives of this group. However, recent studies have found that there is evidence of vocal learning in some species of Trochilidae. The present study focuses on the vocal behavior of the hummingbird Phaethornis superciliosus, abundant species in the Amazon region. This species has a mating system as formation of leks, which is the aggregation of males in a small territory, where they display to other males and females, in order to attract the latter to mate. The aim of this study was to analyze the vocal P. superciliosus arranged in six leks in Gunma Ecological Park, Santa Bárbara do Pará, 50 km north of Belém, considering the issue and physical structure of the song, his repertoire, the frequency of issue throughout the day and year and the dynamics of leks. We found that the population presented a vocal repertoire consisting of two notes that are issued alternately. The songs of the individuals analyzed showed significant differences between them considering the physical parameters of sound (maximum and minimum frequency, duration and interval between the notes and the rhythm of emission of the notes). This inter-individual differentiation may be related to sexual selection, in which the song may allow individual recognition, their social position and its performance for attracting females. We found that the vocal activity is more intense between June and November, a period that probably corresponds to the breeding season. We conducted playback tests, which consist of playing a previously recorded sound and record the response triggered in one of the leks in two different sites, simulating the input of another individual. The playback response is significantly different from the spontaneous song in all parameters. The response to the playback shows the songs that a reduction in the frequency range in which the song was issued and the rate of emission of notes faster. These call features can be related to a more aggressive behavior. The leks are formed in edge areas and always near streams, with the size of the area ranging between 86m2 and 1314m2, composed of two to four individuals 7m to 72m away from each other. Our results showed that the social organization of the lek should be better understood by more detailed studies on the possible meaning that individual differences in the songs may represent for the establishment of the hierarchical position of individuals in the leks.