Wildlife conservation is a crisis discipline aimed at understanding the diversity of life on Earth, investigating human impacts and developing approaches to prevent unnatural species extinctions. An individualistic approach to conservation science and wildlife management can help ensure that individuals and populations can thrive. Consequently, many conservationists apply physiological studies to understand how nutrition, environment, health, behavior, and temperament affect individual's health, reproduction and well-being and wildlife population success. This Research Topic highlights how physiological approaches are applied towards long-term sustainability of wildlife populations. The nine studies within this special issue -organized into three themes-provide useful examples of tools used to obtain physiological data and how that information can benefit population management, both in situ and ex situ.An individual's physiology enables them to cope, or not, within their ever-changing environment. An extreme example of environmental change occurs when wildlife are reintroduced or translocated to aid species recovery and restore a healthier ecosystem. Todd et al. (2026) demonstrate that personality of swift foxes (Vulpes velox) varies with age and between sexes and influences the physiological stress of translocation on individuals. These variations contribute to short-term survival, and the distances animals travel post-release, ultimately impacting translocation outcomes.Indicator species are more sensitive to environmental conditions, thus understanding their physiological state can provide warnings about the impact of anthropogenic disturbance on overall ecosystem health. Ramahlo et al. (2026) validate five non-invasive hormone enzyme immunoassays (EIA) for monitoring six indicator rodent species endemic to the Magaliesberg mountain range in South Africa. Their study neatly demonstrates species-and sex-specific variation in excretion of fecal glucocorticoid metabolites (fGMs). Specifically, three EIA reliably detect fGMs; however, there is no single EIA suitable for all species. This underscores the importance of validating species-specific physiological tools to ensure accurate monitoring and interpretation of stress physiology in wildlife. Dimovski et al. (2025) describe the validation of an alternative non-invasive hormone monitoring method using temporary dermal patches to assess corticosterone and testosterone in amphibians, providing a novel sample collection method to advance physiological research in this taxon. In addition to novel sampling techniques, multi-biomarker approaches are important for understanding downstream effects of stress on animal wellbeing. Allostatic load research estimates the accumulative physiological dysregulation that occurs following exposure to repeated stressors over the lifetime. Although this approach is used widely in humans, in wildlife studies have been more limited and shown mixed results (Seeley et al., 2022). The study by Edes et al. (2025) provides an alternative method, Mahalanobis distance, which may be a useful alternative to allostatic load indexes (ALIs) in nonhuman primates and other taxa, revealing age, sex and birth origin differences in chimpanzees (Pan troglodytes) and bonobos (Pan paniscus), and better prediction of health outcomes.The main goals of ex situ management are to maintain animal well-being and enhance reproductive outcomes. Greggor et al. (2025) investigate whether multi-male mating opportunities improve reproductive success (pregnancy rate, production of litter, litter size, weight gain, offspring weight) and multiple paternity in critically endangered Pacific pocket mice (Perognathus longimembris pacificus). They highlight how using an evidence-based approach to understanding species' physiology and mating system can be beneficial to conservation breeding program management, whether to impact breeding outcomes or maximize genetic diversity of remaining populations. Palanivelan et al. (2025) present a broad overview of the challenges of Asian elephant (Elephas maximus) management amidst the decline in mahouts and the potential loss of traditional knowledge. The study demonstrates that long-term, consistent, and trust-based mahout-elephant relationships and suitable environmental conditions positively influence stress physiology, compliance, successful conservation outcomes and overall wellbeing. The development and implementation of new handling approaches should prioritize elephant health and welfare along with human safety through regulating chaining duration, optimizing feeding strategies, and balancing workload to reduce chronic stress and behavioral issues.Blood parameters such as red and white blood cell counts, electrolyte concentrations, and circulating heavy metal levels are valuable indicators of environmental stressors on animal health. Three papers in this special issue provide baseline blood parameter data that advance our understanding of how environmental changes influence wildlife populations. Allwin et al. (2026) demonstrate that blood samples can be obtained from non-anesthetized tigers (Panthera tigris) and report, for the first time, blood biochemistry and novel biomarkers, Symmetric Dimethylarginine (SDMA), N-terminal pro-Btype natriuretic peptide (NT-proBNP), and cardiac troponin I (cTnI), to elucidate interconnections between renal and cardiac physiology. By examining relationships among renal indicators, metabolic electrolytes, and cardiac biomarkers, the authors provide a diagnostic framework for evaluating renal filtration efficiency, cardiac workload and injury, and metabolic homeostasis. Maçaira et al. (2026) establish hematology and blood biochemistry reference values for brown boobies (Sula leucogaster) and frigatebirds (Fregata magnificens) living in their native habitats in Brazil. Species-specific blood parameters and increased thrombocyte counts compared to earlier studies, are potentially associated with capture-related stress. Additionally, while uric acid and creatine kinase levels in brown boobies and alanine aminotransferase levels in frigatebirds are similar to those in free-ranging birds, they are higher than values observed in individuals maintained in rehabilitation centers, suggesting that dietary differences between in and ex situ populations may contribute to these variations.Finally, Marcelino et al. (2026) report post-mortem analyses of trace minerals and heavy metal concentrations in the livers of minimally managed, multi-species populations of Heck cattle (Bos taurus), Konik horses (Equus caballus), and red deer (Cervus elaphus). The authors identify speciesspecific patterns in trace element profiles and document temporal changes in iron and lead across the three species, providing baseline data for environmental and health monitoring to support wildlife health assessments.Together, these nine studies highlight the importance of developing and validating new tools for the assessment of ecophysiology in wildlife, to provide greater understanding of how individuals and populations across taxa respond to changing environments and allow an evidence-based approach to their conservation. Further, the diversity of journals in which the studies are published, including Frontiers in Animal Science, -Conservation Science, and -Veterinary Science, underscores the wide applicability of physiological research to wildlife biology and management.
Freeman et al. (Tue,) studied this question.