Search

High Andean lizards in the Andes face numerous challenges in high‐altitude environments characterized by significant temperature, spatial and temporal variations. These factors greatly influence their thermal characteristics and adaptive strategies for coping with temperature fluctuations. This study aims were to investigate the thermal biology of high mountain lizards (>2000 m) inhabiting the Andes Mountain range, using information from existing literature, and to identify the potential impacts of the original climate change scenarios developed in this study. Within the Andes, high‐altitude species are primarily found in families like Liolaemidae, Gymnophthalmidae, Tropiduridae, Anolidae and Leiourisauridae. Notably, we found in the literature that the higher body temperatures and maximum critical temperatures in southern species compared to those closer to the tropics. Typically, diurnal and seasonal temperature variations have a significant impact on the body temperature of these high‐altitude lizards, but their adaptive behaviours and physiological mechanisms enhance their resistance to extreme temperatures. Populations situated below the equator often exhibit higher body temperatures and maximum critical temperatures, largely due to their exposure to higher ambient temperatures during summer. With all global warming scenarios indicating temperature increases in latitudinal regions, tropical high‐altitude lizards, historically less thermally adaptable, may be particularly susceptible to these temperature rises. It is crucial to consider that additional factors, such as species activity patterns, thermal resource availability and diminishing suitable thermal habitats, will also play a pivotal role in shaping the future of these lizard species, making the situation even more complex and challenging. [ABSTRACT FROM AUTHOR]

Tardigrades, are a phylum of microscopic organisms well known for their resistance to extreme conditions thanks to adaptations such as cryptobiosis, in which they are able to suspend their metabolism until more favorable conditions arise. These organisms are found in a wide range of environments, and high Andean mountains are not the exception, even though weather conditions are highly variable during the day, let alone a month. An experiment was conducted at an altitude of 2600 m in Bogotá, Colombia, to evaluate the resistance of Macrobiotus sp. found on trees. Three sets of fifteen tardigrades were exposed to temperatures of 20 °C, 30 °C, and 40 °C, with a heating rate of 0.5 °C/min. The tardigrades were then examined to determine the number of living, dead, and "tun" organisms. At 20 °C, 22% of the individuals were dead; at 30 °C, 35.56% were dead; and at 40 °C, 46.67% were dead. No tardigrades were found in the "tun" state at any temperature. Therefore, the data show an increase in mortality as the temperature rises. However, considering the climatic conditions recorded, studied tardigrades are able to withstand higher temperatures than those they are usually exposed to. The lack of the "tun" state implies that high temperatures, at least at this rate, do not trigger this state, whereas conditions like desiccation might. More research is needed to explore this further. [ABSTRACT FROM AUTHOR]

The article focuses on describing the release calls of Atelopus nahumae, an endemic and endangered frog species from the Sierra Nevada de Santa Marta in Colombia. Topics discussed include the ecological role of anuran vocalizations, the methodology used to record and analyze the release calls, and the implications of these vocalizations for the conservation of A. nahumae.

The article reports on localities for the Harlequin frog Atelopus laetissimus in the Sierra Nevada de Santa Marta, Colombia, which extend its lower altitudinal limit. Topics discussed include the discovery of another life zone for the specie, temperature data from different microhabitats used, and the differences between extreme temperatures among localities.