Papers by Francisco Fonseca Ribeiro de Oliveira
Journal of Natural History, 2012
The breeding biology and male territorial behaviour of the large-headed leaf-frog (Phyllomedusa m... more The breeding biology and male territorial behaviour of the large-headed leaf-frog (Phyllomedusa megacephala) were studied in three temporary altitudinal streams located in the Cerrado biome of southeastern Brazil, during three consecutive years (2007–2009). Phyllomedusa megacephala showed significant sexual dimorphism, with females being bigger and heavier than males. Acoustic and physical interactions between males defending or not defending territories including amplectant and non-amplectant males, patrolling behaviour by males without established territories, and triple amplexus were observed. Neither males nor females were observed using visual cues when searching for mates. We found that males that were present at breeding sites in previous years bred more successfully and maintained territory better.
Acta Oecologica-international Journal of Ecology, 2009
We studied anuran assemblage composition from 1st to 4th orders along two rivers in the Rio Preto... more We studied anuran assemblage composition from 1st to 4th orders along two rivers in the Rio Preto State Park, southeastern Brazil. We aimed to understand how species distribution relates to local features/ longitudinal gradients within a river, and to differences between rivers. We assessed climatic (temperature, humidity), chemical (water pH, dissolved oxygen, conductivity), physical (river bottom type, current), and biotic (vegetation structure) features thought to affect anuran distribution. Cluster analyses showed that species assemblages tended to be more similar among sections of the same river than between corresponding sections of different rivers, and Mantel tests showed assemblages to be spatially structured, although river features were not. The river with a mixture of open vegetation and forest at its margins sheltered higher species diversity than the one bordered by forest. Using Canonical Correspondence Analyses, we found variables related to microhabitat availability to be the best ones to explain species distribution in the adult stage, and conductivity to be the best one for the tadpole stage. The river seasonal flood pulse seems to influence availability of additional reproductive sites and tadpole dispersal. We found no evidence of gradients of tadpole abundance responding to river size or predator abundance. Considering that anuran species are spatially structured and influenced by variables that change both locally and regionally, we recommend that the whole longitudinal gradient along permanent lotic ecosystems, together with its original limnological and structural attributes, is preserved in order to ensure conservation of anuran diversity in both local and regional scales.
Acta Oecologica-international Journal of Ecology, 2009
We studied anuran assemblage composition from 1st to 4th orders along two rivers in the Rio Preto... more We studied anuran assemblage composition from 1st to 4th orders along two rivers in the Rio Preto State Park, southeastern Brazil. We aimed to understand how species distribution relates to local features/ longitudinal gradients within a river, and to differences between rivers. We assessed climatic (temperature, humidity), chemical (water pH, dissolved oxygen, conductivity), physical (river bottom type, current), and biotic (vegetation structure) features thought to affect anuran distribution. Cluster analyses showed that species assemblages tended to be more similar among sections of the same river than between corresponding sections of different rivers, and Mantel tests showed assemblages to be spatially structured, although river features were not. The river with a mixture of open vegetation and forest at its margins sheltered higher species diversity than the one bordered by forest. Using Canonical Correspondence Analyses, we found variables related to microhabitat availability to be the best ones to explain species distribution in the adult stage, and conductivity to be the best one for the tadpole stage. The river seasonal flood pulse seems to influence availability of additional reproductive sites and tadpole dispersal. We found no evidence of gradients of tadpole abundance responding to river size or predator abundance. Considering that anuran species are spatially structured and influenced by variables that change both locally and regionally, we recommend that the whole longitudinal gradient along permanent lotic ecosystems, together with its original limnological and structural attributes, is preserved in order to ensure conservation of anuran diversity in both local and regional scales.
Crypsis results from a complex interaction among prey coloration, background matching, behaviour ... more Crypsis results from a complex interaction among prey coloration, background matching, behaviour and predator visual perception. Tadpoles are known to have varied adaptations to escape predation, but the use of crypsis is little explored, although it is likely for certain species. We investigated potential escape mechanisms related to active escape (fleeing) and crypsis improvement in Bokermannohyla alvarengai tadpoles, proposing a new method to measure cryptic potential. We studied the range of distances covered by threatened and fleeing tadpoles and the proportion of tadpoles that seek shelter or remain exposed after fleeing. We hypothesized that tadpoles that remain exposed may use alternative strategies to avoid detection, such as reaching deeper microhabitats or positioning themselves on substrates that confer greater crypsis than the ones they were on before disturbance. A significantly greater proportion of tadpoles remained exposed after disturbance and positioned themselves on backgrounds that offered greater cryptic potential, but did not differ in depth. Tadpoles may respond to a trade-off between sheltering and being cryptic. On the one hand, they may remain close to retreat sites or they may escape to microhabitats that provide appropriate background matching as a means to achieve crypsis. On the other hand, the absence of matching backgrounds in the tadpoles' vicinities may induce them to seek shelter.
We conducted a capture-mark-release study of small mammals in an urban forest fragment at the Par... more We conducted a capture-mark-release study of small mammals in an urban forest fragment at the Parque das Mangabeiras, in the city of Belo Horizonte, southeastern Brazil. Four marsupials -Didelphis albiventris Lund, Gracilinanus agilis (Burmeister), Marmosops incanus (Lund), Philander frenatus (Olfers) -and four rodents -Sciurus aestuans Linnaeus, Akodon montensis Thomas, Rhipidomys mastacalis (Lund) and Mus musculus Linnaeus -were found between March 2003 and February 2004. The most abundant species were M. incanus and S. aestuans, representing respectively 50% and 20% of the individuals recorded. Terrestrial habits were detected for A. montensis and D. albiventris, scansorial habits for G. agilis, M. incanus, P. frenatus, and S. aestuans, while R. mastacalis was exclusively arboreal. There was positive correlation between rainfall and population abundance for D. albiventris, and positive correlation between recruitment rates and rainfall for M. incanus. Rapid turnover rates suggested short residence time for most species. Three reproductive patterns were identified: prolonged reproduction during both seasons in R. mastacalis, reproduction during the dry season in G. agilis, and reproduction during the wet season in the remaining species. Only individuals of D. albiventris, M. incanus, R. mastacalis, and S. aestuans were detected across the paved road that runs through the fragment, suggesting that the road may be a barrier to the other species.
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Papers by Francisco Fonseca Ribeiro de Oliveira