Biology subjects

Miranda, R. B.

Publications and source records attributed to Miranda, R. B..

2 recordsLinked to original sources

bioRxiv2025

Thermophysiology or resource availability: What shapes the post-flooding abundance of lizard species across artificial islands in a Neotropical biome?

Global warming has led to increased flooding events, causing significant habitat fragmentation and affecting species distribution in tropical ecosystems. This study investigates the postflooding abundance of lizard species across artificially created islands in the Cerrado biome, focusing on the roles of thermophysiological traits and resource availability. We conducted a comprehensive survey, recording 560 individual lizards representing 13 species from eight families, and used generalized additive models to assess the impact of mean field-active body temperature and net primary productivity on lizard abundance. Our results indicate that a rise in mean field-active body temperature significantly correlates with reduced lizard abundance, supporting the physiological tolerance hypothesis. This finding points out the critical importance of thermoregulation for ectotherm survival in the face of climate change. Conversely, resource availability, measured through net primary productivity, showed no significant effect on lizard abundance. These findings bring to light the vulnerability of lizard populations to thermal stress and emphasize the necessity for conservation strategies that prioritize the creation of thermal refuges and improve habitat connectivity to mitigate the impacts of rising temperatures. By integrating species traits into macroecological analyses, our study offers valuable insights for biodiversity conservation in fragmented landscapes. Future research should explore diverse ecosystems to validate these findings, thereby informing effective conservation planning and ensuring the resilience of ectotherm populations in altered environments.

ecology↗

bioRxiv2024

How do body size and habitat fragmentation influence extinction in lizards? A long-term case study on artificial islands in the Brazilian Cerrado

Habitat fragmentation is known to cause extinctions and species turnover, but the factors that allow some species to persist while others become locally extinct are not well understood. Landscape flooding following the construction of hydroelectric dams causes a particularly dramatic form of fragmentation disturbance, where former terrestrial habitats become aquatic and former hilltops become land-bridge islands. As such, reservoir land-bridge islands have become a successful model for accessing the impacts of fragmentation on biodiversity. We used the lizard community, to assess species sensitivity to habitat structural change during land-bridge island formation. We monitored the lizard community for 23 years before, during, and after the flooding of the Serra da Mesa Dam reservoir. Over the course of our study, the diversity of the lizard community on land-bridge islands and mainland sites along the shores of the newly formed reservoir declined from 19 to six species. We found that in Serra da Mesa islands, lizards with large body sizes (e.g., Teiidae and Tropiduridae) decreased in abundance along the flooding process, thereby increasing their extinction risk. In contrast, we found a high abundance of small-bodied lizards (Gekkonidae, Gymnophthalmidae, Scincidae, and Sphaerodactylidae) on Serra da Mesa islands. Richness on the islands declined dramatically, resulting in communities currently with one highly abundant species, Gymnodactylus amarali. For the sake of biodiversity conservation, island or fragment sizes must be considered for maintaining a reasonable number of species and our characterization of the local extinction patterns may provide relevant information to mitigate wildlife depletion due to habitat fragmentation.

ecology↗