Publications by authors named "Marcela A Vidal"
Article Synopsis
- - The study analyzed the thermal performance curve (TPC) of five species of amphibia (Eupsophus) in southern Chile, focusing on how temperature affects their locomotor abilities under different environmental conditions.
- - Results indicated that these species have relatively consistent thermal responses, showing narrow thermal windows for activity compared to other local species, while also exhibiting significant individual differences in performance across varying temperatures.
- - The research suggested a trade-off between thermal tolerance and locomotor performance, hinting that species with broader temperature ranges may experience reduced performance, and these traits are influenced by body size, raising ecological questions.
Article Synopsis
- Global biodiversity conservation is constrained by limited resources, necessitating the identification of conservation priorities, particularly for amphibians in Chile.
- A study evaluated 58 amphibian species, classifying them into priority categories based on conservation needs, with findings indicating that 70% of these species are threatened mainly by habitat loss, pollution, and diseases.
- Eight amphibian families were highlighted for conservation, and 14 species were identified as needing further research, emphasizing the importance of informed management strategies to address the threats they face.
Article Synopsis
- The Atacama Desert's evaporitic ecosystems are home to a unique freshwater snail, which is critically endangered and faces threats from climate changes and landscape variations.
- A study found that this snail has distinct genetic groups that correlate with environmental conditions, revealing significant differences in shell shape across geographically isolated populations.
- Given the findings, the snail's conservation status has been updated to Endangered regionally, emphasizing the need for conservation strategies that incorporate its genetic diversity.
Article Synopsis
- A comprehensive assessment of reptile extinction risks reveals that 21.1% of reptile species, or 1,829 out of 10,196, are threatened, highlighting the urgent need for conservation strategies amidst global extinction crises.
- Similar to other tetrapods like amphibians, mammals, and birds, reptiles face threats from agriculture, logging, urban development, and invasive species, with forest-dwelling reptiles being at a higher risk than those in arid environments.
- Although some reptile species need immediate action for conservation, broader efforts targeting other tetrapods, such as habitat protection and managing invasive species, could also benefit many reptile species.
Amphibian responses in experimental thermal gradients: Concepts and limits for inference.
Comp Biochem Physiol B Biochem Mol Biol
July 2021
Article Synopsis
- The interpretation of thermal-gradient data is influenced by assumed behavioral drives, particularly in amphibians, which may display a range of thermal responses beyond the commonly accepted positive thermotaxis model.
- The authors present a historical review and suggest that amphibians might exhibit alternative behavioral drives like negative thermotaxis, influenced by temperature settings as well as their evolutionary history and development stages.
- They emphasize the need for careful analysis when inferring behavioral drives from thermal gradients, proposing that "selected temperatures" and "preferred temperatures" should be viewed as distinct concepts, with implications for ecological modeling and understanding disease dynamics.
Article Synopsis
- The sewage snail Physa acuta, an invasive species from North America, was first found in Chile in 2014, but hasn't been seen in the southern part of the country until recent collections in 2018.
- New samples from Llanquihue Lake matched the characteristics of Physa acuta through detailed morphological and genetic analyses, confirming its presence in the region.
- The study emphasizes the need for immediate actions to prevent further spread of this invasive snail in Llanquihue Lake and surrounding aquatic environments.
Article Synopsis
- Amphibian movement is influenced by both temperature and hydration, but organisms face multiple environmental factors simultaneously in nature.
- To study these effects, researchers examined two populations of a small amphibian from environments with very different temperatures and rainfall.
- Findings revealed that locomotor performance improved with higher temperatures and better hydration, plateauing at 25-30°C, and that the warmer environment population showed less impact on movement from dehydration, suggesting a possible adaptation to heat.
Article Synopsis
- - The identification of minute freshwater snails in Chile is challenging due to similarities in shell morphology, which is complicated by the presence of invasive species like Potamopyrgus antipodarum sharing the habitat with native genera Heleobia and Potamolithus.
- - Through a combined molecular phylogenetic analysis and examination of reproductive and morphological traits, researchers identified various snail species across 51 locations, revealing 10 sites with the invasive mudsnail, 23 with Heleobia, and 7 with Potamolithus.
- - The study highlights significant findings regarding the spread of the invasive mudsnail, suggesting potential species replacement and extinction of native snails, emphasizing the importance of integrative taxonomy for addressing complex species identification in ongoing invas
Article Synopsis
- Global climate change is expected to have a more significant effect on ectotherms, like amphibians, in tropical and subtropical regions due to their reliance on external temperatures that are already near their limits.
- The Great Chilean frog (Calyptocephalella gayi) faces threats from over-exploitation and habitat loss, making it a Vulnerable species, but little is known about its ability to adapt to changing temperatures.
- Research indicates that while C. gayi can handle temperatures up to 30°C, around 40% of subadults and 47% of adults may not survive a projected 7°C increase over the next 85 years, jeopardizing future populations.
Article Synopsis
- Clinal variation refers to gradual changes in a characteristic related to geographic distance, as seen in a medium-large lizard species living in northern Chile's intertidal zone, covering a range from Antofagasta to La Serena.
- The study utilized geometric morphometrics to analyze head shape variation across five locations, specifically looking at dorsal and lateral views, but found no significant differences in shape among these areas or between sexes.
- The conclusion suggests that similar environmental conditions across populations may lead to convergence in head shape, explaining the lack of differentiation in form despite geographical variation.
Stable isotopes document mainland-island divergence in resource use without concomitant physiological changes in the lizard Liolaemus pictus.
Comp Biochem Physiol B Biochem Mol Biol
May 2010
Article Synopsis
- Shifts in feeding ecology can lead to differences between island and mainland lizard subspecies, specifically in Liolaemus pictus found in Chile.
- The study analyzed both stomach contents and nitrogen stable isotope ratios to examine dietary habits and found that mainland lizards had a higher trophic level despite shorter intestines and more active digestive enzymes compared to island lizards.
- The findings indicate that while morphology and physiology differ among lizard populations, these differences are not necessarily linked to their feeding ecology, suggesting that behavioral adaptations may be the initial response to dietary changes.