Orestias ascotanensis is a killifish endemic to the Ascotán salt pan in the Chilean Altiplano, where it inhabits 12 springs with different degrees of

Se analizó la dieta del pequén (Athene cunicularia) en cuatro islas del norte de Chile, mostrando que existe un fuerte predominio de artrópodos (89,1%) en comparación con los vertebrados (10,1%) respecto al número de presas consumidas. De estos taxa destacan los tenebriónidos (42,2%) y curculiónidos (31,2%) como los principales grupos consumidos, sin embargo, la presencia de mamíferos (3,6%) y de aves (6%) en la dieta es también relevante, ya que a pesar de representar menos del 10% del número total de presas, el aporte energético de estos vertebrados constituyó cerca del 80% de la biomasa total ingerida. Se registró evidencias de depredación sobre el yunco (Pelecanoides garnotii); presa destacada con un 71% dentro del ítem aves y 40% del total de vertebrados consumidos, así también destaca el consumo de la llaca (Thylamys elegans) con en un 21% del total de vertebrados. Se encontraron tres individuos de piuchén o vampiro (Desmodus rotundus) especie no descrita con anterioridad en la dieta del pequén en el norte de Chile. Se discute respecto a las posibles respuestas funcional y numérica del pequén en isla Choros, asociadas a los registros de distintas densidades de yunco. Se analizó además, la variabilidad de la dieta por isla, el patrón de tamaño de las presas consumidas y la distribución espacial de nidos del pequén.

The Andean Altiplano, characterized by its extreme climatic conditions and high levels of biodiversity, provides a unique environment for studying ecological and evolutionary adaptations in insect morphology. Butterflies, due their large wing surface compared to body surface, and wide distribution among a geographical area given the flight capabilities provided by their wings, constitute a good biological model to study morphological adaptations following extreme weathers. This study focuses on Phulia nymphula, a butterfly species widely distributed in the Andes, to evaluate wing shape variation across six localities in the Northern Chilean Altiplano. The geometric morphometrics analysis of 77 specimens from six locations from the Chilean Altiplano (Caquena, Sorapata Lake, Chungará, Casiri Macho Lake, Surire Salt Flat, and Visviri) revealed significant differences in wing shape among populations. According to the presented results, variations are likely influenced by local environmental conditions and selective pressures, suggesting specific adaptations to the microhabitats of the Altiplano. The first three principal components represented 60.92% of the total wing shape variation. The detected morphological differences indicate adaptive divergence among populations, reflecting evolutionary responses to the extreme and fragmented conditions of the Altiplano. This study gives insights into the understanding of how high-altitude species can diversify and adapt through morphological variation, providing evidence of ecological and evolutionary processes shaping biodiversity in extreme environments.

Island ecosystems differ in several elements from mainland ecosystems and may induce variations related to natural selection and patterns of adaptation in most aspects of the biology of an organism. Thylamys elegans (Waterhouse, 1839) is a marsupial endemic to Chile, distributed from Loa River to Concepción. Historically, three subspecies have been described: Thylamys elegans elegans, Thylamys elegans coquimbensis and Thylamys elegans soricinus. For this research, two morphometric approaches and a biomechanical model were used to compare the mandible shapes and biomechanics between two Chilean mouse opossum populations belonging to different subspecies: one from the coastal desert of Chile (T. e. coquimbensis) and the other from the central inland region (T. e. elegans). Additionally, mandibles of insular populations found in the Reserva Nacional Pinguino de Humboldt (RNPH)), from which the subspecies association is unknown, were also included. The results showed that insular populations have differences in mandibular shapes, sizes and biomechanical characteristics compared to continental populations, which may be related to environmental variables like aridity and vegetation cover, prey type, insularity effects and/or the founder effect on micromammals, apart from vicariance hypotheses and other selective pressures.

Islands provide valuable opportunities to study how isolation affects phenotypic variation. Even though orchid bees are highly mobile, their movement can still be restricted by marine barriers. In this study, we assessed whether insular isolation impacts wing shape in the orchid bee Euglossa mixta across the Coiba archipelago and a nearby mainland site in Western Panama. Our study analyzed 271 individuals using geometric morphometrics, focusing on forewing venation landmarks, and evaluated the variation using multivariate analyses of shape variation and quantifying the shape of Mahalanobis distances. Additionally, we conducted a Mantel test to explore the relationship between geographic distance and morphological divergence. Our findings reveal that wing shape variation in E. mixta is largely conserved but shows fine-scale structuring consistent with spatial patterns expected in insular systems. These results suggest that even highly mobile pollinators may experience enough isolation for subtle phenotypic shifts to occur, highlighting the sensitivity of geometric morphometrics for detecting early stages of morphological differentiation.