Mariana Nascimento Siqueira

Males of Hypsiboas goianus (Anura; Hylidae) do not assess neighbor fighting ability through acoustic interactions

In frogs, acoustic signals are the most important communication mechanism, since they may be used in several social contexts. In many anurans, the dominant frequency of calls is negatively related to body size, and in such species, this spectral parameter may be considered a good predictor of fighting ability. We experimentally investigated the vocal behavior of 30 male Hypsiboas goianus in central Brazil to answer the following questions: (1) Do males change the acoustic parameters of their calls in response to conspecific intruders? and (2) Does the acoustic behavior of H. goianus depend on the simulated body size of their opponent? We used playback of synthesized calls with high (3573 Hz) and low (3123 Hz) dominant frequency to simulate small and large males, respectively. Males reduced the rate of advertisement calling in response to playback but did not change vocal behavior in response to low-frequency and high-frequency playback. So, while males adjust their calling activity in response to simulated conspecifics, there was no evidence that they assess the fighting ability of their opponents through acoustic interactions.

Análise geoecológica da conservação ambiental das sub-bacias do Rio Claro (GO) e do Rio Garças (MT)

Estudos direcionados a caracterizacao de paisagens heterogeneas vem sendo favorecidos pela associacao a analise geoecologica com indices (metricas) descritores da paisagem. O objetivo do trabalho foi o de avaliar o estado de conservacao da paisagem atraves da analise da fragmentacao dos remanescentes de Cerrado nas sub-bacias do rio Claro e do rio Garcas, situadas na Alta Bacia do rio Araguaia com base em mapas de uso da terra, do ano de 2010 e calculo dos indices descritores da paisagem com uso do software FRAGSTATS. Os resultados indicam que as sub-bacias apresentam situacoes contratantes de conservacao entre as fitofisionomias e classes de uso, mas que ainda e possivel, em funcao dos resultados indicados pelas metricas de conectividade a conservacao ambiental nas areas, apos planejamentos especificos.

Geografia e ecologia da paisagem: pontos para discussão

This paper discusses some aspects about the landscape concept and it contributions to understand the conceptual evolution of landscape according to geography and ecology. Respectively, these approaches, geographic and ecologic, emphasize the spatial analysis of landscape elements and the biological alteration and the ecological relations that are developed. Therefore, due to point view theorical and methodological, the Geoecology term has been rescued to integrate the geographic and ecological approaches. However, both approaches have used geotecnologies in identification and mapping of landscape units. Thus, it is possible to highlight that human appropriation of ecosystems is intense and transforming, therefore this factor must be considered in concept, structure and dynamic of landscapes. Keysword: landscape ecology, Geoecology, fragmentation, remnant, geotecnologies.