Análise do repertório vocal de Pitangus sulphuratus (Linnaeus, 1766) (Aves: Passeriformes: Tyrannidae) em diferentes regiões do Brasil
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Data
2017-07-28
Autores
Rodrigues, Fernanda Gonçalves [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
O bem-te-vi, Pitangus sulphuratus, é um dos pássaros mais comuns em quase todo o Brasil e considerado o mais popular deste país. Apresenta um comportamento altamente versátil e generalista, e encontra alimento facilmente em qualquer hábitat, tendo uma ampla distribuição geográfica, sendo encontrado do Texas ao sul da Argentina. No Brasil ocorrem quatro subespécies, que apresentam diferenciações nas cores da plumagem do dorso e do ventre. Inserido na Classe Aves, ordem Passeriformes, subordem Suboscines, tem o seu canto considerado inato, já que se desenvolve normalmente na ausência de um modelo auditivo. As aves Suboscines são bons modelos de análise vocal entre populações, já que quaisquer diferenças entre suas vocalizações não poderiam ser atribuídas aos padrões culturais de aprendizado. Considerando-se que o ambiente exerce uma seletividade na transmissão do som, indivíduos de uma mesma espécie podem apresentar diferenças vocais por estarem em ambientes diferentes; sendo assim, a localização pode exercer uma padronização ou diferenciação nas vocalizações das aves. Neste trabalho foram utilizadas 288 vocalizações de Pitangus sulphuratus, os quais foram classificados de acordo com sua sintaxe. Realizaram-se análises estruturais acústicas para a comparação e identificação de possíveis variações vocais entre as populações das subespécies presentes no Brasil e correlação com a altitude, latitude, longitude, bem como variáveis bioclimáticas (temperatura e precipitação). Foram identificadas oito sílabas diferentes, que combinadas compõem os três tipos de vocalizações presentes no repertório da espécie. A vocalização principal e a vocalização da aurora apresentaram sintaxe combinatória, que ocorre quando a ave muda a posição das sílabas nas vocalizações. O tempo entre as sílabas A e B relacionou-se positivamente com a longitude; já o tempo da sílaba A teve relação negativa. Ou seja, quanto maior a longitude, maior o tempo entre A e B e menor o tempo de A. Já as variáveis de tempo das sílabas B, C e tempo total do trecho se relacionaram negativamente com a latitude, apresentando menor duração conforme o indivíduo se aproxima da linha do Equador. Os valores de frequência se relacionaram negativamente com a altitude e com a temperatura e positivamente com a umidade, portanto, conforme aumenta a umidade, e ocorre a diminuição da temperatura, os valores de frequência tendem a aumentar, e quanto maior a altitude menores as frequências. Já as diferenças vocais e as distâncias geográficas, que representavam as localidades das subespécies, não apresentaram relação. Isto indica que as diferenças nas vocalizações não estão relacionadas com as populações das subespécies, podendo ser uma variação individual.
The Great Kiskadee, Pitangus sulphuratus, is one of the most common birds in almost all Brazil, appearing in almost the entire Brazilian territory and considered the most popular of this country. It presents a highly versatile and generalist behavior, and finds food easily in any habitat, having a wide geographical distribution, being found from Texas to the south of Argentina. In Brazil there are four subspecies, which show differences in the colors of the plumage of the back and the belly. It is classified in the Order Passeriformes, suborder Suboscines, its song is considered innate, since it develops normally in the absence of an auditory model. Suboscine birds are good models of vocal analysis among populations, since any differences between their vocalizations could not be attributed to cultural patterns of learning. Considering that the environment exerts selectivity in sound transmission, individuals of the same species may present vocal differences because they are in different environments. Thus, localization can exert a standardization or differentiation in the vocalizations of birds. In this work 288 vocalizations of Pitangus sulphuratus were used, which were classified according to their syntax. Acoustic structural analysis was performed for the comparison and identification of possible vocal variations between subspecies populations in Brazil and correlation with altitude, latitude, longitude, as well as bioclimatic variables (temperature and precipitation). Eight different syllables were identified, which combined make up the three types of vocalizations present in the repertoire of the species. The main vocalization and dawn song presented combinatorial syntax, which occurs when the bird changes the position of the syllables in the vocalizations. The time between the syllables A and B was positively related to the longitude. However, the time of syllable A had negative relation. That is, the longer the length, the longer the time between A and B and the shorter the time of A. The time variables of the syllables B, C and total time of the section were negatively related to the latitude, presenting a shorter duration according to the individual is approaching the Equator. Frequency values are negatively related to altitude and temperature and positively to humidity, therefore, as humidity increases, and temperature decreases, frequency values tend to increase, and the higher the altitude, the lower the frequencies. The vocal differences and the geographical distances, that represented the localities of the subspecies, did not present relation. This indicates that the differences in vocalizations are not related to subspecies populations, and may be an individual variation.
The Great Kiskadee, Pitangus sulphuratus, is one of the most common birds in almost all Brazil, appearing in almost the entire Brazilian territory and considered the most popular of this country. It presents a highly versatile and generalist behavior, and finds food easily in any habitat, having a wide geographical distribution, being found from Texas to the south of Argentina. In Brazil there are four subspecies, which show differences in the colors of the plumage of the back and the belly. It is classified in the Order Passeriformes, suborder Suboscines, its song is considered innate, since it develops normally in the absence of an auditory model. Suboscine birds are good models of vocal analysis among populations, since any differences between their vocalizations could not be attributed to cultural patterns of learning. Considering that the environment exerts selectivity in sound transmission, individuals of the same species may present vocal differences because they are in different environments. Thus, localization can exert a standardization or differentiation in the vocalizations of birds. In this work 288 vocalizations of Pitangus sulphuratus were used, which were classified according to their syntax. Acoustic structural analysis was performed for the comparison and identification of possible vocal variations between subspecies populations in Brazil and correlation with altitude, latitude, longitude, as well as bioclimatic variables (temperature and precipitation). Eight different syllables were identified, which combined make up the three types of vocalizations present in the repertoire of the species. The main vocalization and dawn song presented combinatorial syntax, which occurs when the bird changes the position of the syllables in the vocalizations. The time between the syllables A and B was positively related to the longitude. However, the time of syllable A had negative relation. That is, the longer the length, the longer the time between A and B and the shorter the time of A. The time variables of the syllables B, C and total time of the section were negatively related to the latitude, presenting a shorter duration according to the individual is approaching the Equator. Frequency values are negatively related to altitude and temperature and positively to humidity, therefore, as humidity increases, and temperature decreases, frequency values tend to increase, and the higher the altitude, the lower the frequencies. The vocal differences and the geographical distances, that represented the localities of the subspecies, did not present relation. This indicates that the differences in vocalizations are not related to subspecies populations, and may be an individual variation.
Descrição
Palavras-chave
Bem-te-vi, Suboscines, Sintaxe, Bioacústica, Variação da vocalização, Great Kiskadee, Syntax, Bioacoustics, Variation of vocalization