Evolutionary ecophysiology in extreme environments under a global change scenario

As wildlife increasingly has to face levels of environmental conditions that go far beyond normal ranges, understanding the ecological and evolutionary dynamics behind such extreme scenarios becomes essential for animal conservation. Here, we discuss the eco-physiological singularities of wildlife coping with extreme conditions. We first discuss the conditions under which scenarios can be considered 'extreme'. This includes distinguishing the nature of natural and anthropogenic disturbances, considering aspects such as their intensities, as well as the understanding of species biology and evolutionary history. To exemplify the diversity of wildlife responses to extreme conditions, we highlight five different representative study cases (two with natural causes, three of anthropogenic origin): birds at high altitude, fish in geothermal habitats, birds in pesticide-laden farmlands, invertebrates in urban ponds, and amphibians in radioactive zones. These examples illustrate the diverse physiological and ecological responses to extreme factors, emphasizing the complexity of wildlife adaptation under different scenarios. However, they also reveal significant knowledge gaps regarding long-term effects of responses to extreme environments, and the mechanistic basis behind these processes. Future research should ideally include long-term approaches making use of validated physiological markers of individual, population or species health or fitness. This information could be then incorporated into mechanistic models like Species Distribution Models (SDMs) to predict species geographic occurrence and the impact of future extreme scenarios. Such holistic and integrative physiological approaches will enhance our understanding of species and population resilience, and will facilitate the identification of vulnerable populations, ultimately improving management strategies. By prioritizing these research efforts, we will better anticipate the impacts of environmental changes on wildlife health, and thus improve biodiversity conservation strategies.