Processos ecológicos e evolutivos na comunicação acústica entre grilos: partição de nicho acústico e seleção de sítios de chamado

• Autor(a) principal: Oliveira, Gabriel Lobregat de
• Data de Publicação: 2014
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/3230
• topic: Grilo; Grylloidea; Interferência sonora; Bioacústica; Som de chamado; cricket; Grylloidea; Noise interference; bioacoustics; Calling song; CNPQ::CIENCIAS BIOLOGICAS::ECOLOGIA

Acoustic communication is used by a large amount of animals for the search of sexual mates to be easier and reducing energy spent on it. For communication to be successful, signals must undergo three processes: production by a sound source, propagation through the environment, and reception by the target receiver. Due to its intimate relationship to reproductive success, natural selection benefits adaptations that raises the efficiency of signals to reach the receiver and minimize sound interference with other sounds. In the present work, we assessed questions related to the three processes of acoustic communication: production, propagation and receiving. In the first chapter, we study an Atlantic Forest cricket assemblage and evaluated possible ecological processes of acoustic activity inhibition in response to sound similarity. We also evaluated processes of acoustic signals differentiation by using null models approach on the calling song parameteres. We found that resemblance between species in their calling song temporal components was negatively correlated to temporal coocurrence between them, but no influence of coocurrence in frequency similarities. We also observed regular spacing between species sound frequencies, whereas differences in temporal components of signals didn t differ from the null model. Thus, we infer that species with similar temporal parameters minimize sound interference by avoiding calling together. Even spacing in sound frequency values are evidences of community-wide selective pressures that lead to regular partitioning of sound space. In the second chapter, we evaluated the behavioral strategies during sound emission, the possible agonistic interactions and calling site use regarding height and leaf blade dimensions in two sympatric cricket species (Phylloscyrtus amoenus and Cranistus colliurides) with similar sound frequencies. We found that both species presented similar stridulation behavior, using leaf surfaces as sound baffles and emitting acoustic signals to multiple directions. We observed intra and interspecific agonistic interactions related to calling site dispute. Calling sites of both species were similar in leaf dimensions, but different in height. The stridulation behavior provides us evidences of maximization of acoustic signals range. Agonistic interactions seems to be related to dispute for better calling sites to emit acoustic signals. Similarities in leaf dimensions may be related to the similarities in their sound frequencies, so their signals suffer the same constraints imposed by obstacles.