Conservation physiology and the quest for a 'good' Anthropocene

Conservation physiology and the COVID-19 pandemic

The COVID-19 pandemic and associated public health measures have had unanticipated effects on ecosystems and biodiversity. Conservation physiology and its mechanistic underpinnings are well positioned to generate robust data to inform the extent to which the Anthropause has benefited biodiversity through alterations in disturbance-, pollution- and climate change-related emissions. The conservation physiology toolbox includes sensitive biomarkers and tools that can be used both retroactively (e.g. to reconstruct stress in wildlife before, during and after lockdown measures) and proactively (e.g. future viral waves) to understand the physiological consequences of the pandemic. The pandemic has also created new risks to ecosystems and biodiversity through extensive use of various antimicrobial products (e.g. hand cleansers, sprays) and plastic medical waste. Conservation physiology can be used to identify regulatory thresholds for those products. Moreover, given that COVID-19 is zoonotic, there is also opportunity for conservation physiologists to work closely with experts in conservation medicine and human health on strategies that will reduce the likelihood of future pandemics (e.g. what conditions enable disease development and pathogen transfer) while embracing the One Health concept. The conservation physiology community has also been impacted directly by COVID-19 with interruptions in research, training and networking (e.g. conferences). Because this is a nascent discipline, it will be particularly important to support early career researchers and ensure that there are recruitment pathways for the next generation of conservation physiologists while creating a diverse and inclusive community. We remain hopeful for the future and in particular the ability of the conservation physiology community to deliver relevant, solutions-oriented science to guide decision makers particularly during the important post-COVID transition and economic recovery.

Health status of Polychrus gutturosus based on physical examination, hematology and biochemistry parameters in Costa Rica

Studies evaluating the health status and characteristics of free-ranging wildlife populations are scarce or absent for most species. Saurian health assessments are usually performed in species that have conservation issues or that are kept in captivity. The Berthold’s bush anole (Polychrus guturossus) is one of eight species belonging to the genus Polychrus, the only representative of the family Polychrotidae. Only a handful of studies have been reported concerning these lizard’s morphological variation, ecology, and natural history, probably because P. gutturosus is a canopy dweller and it can be difficult to locate individuals. It is believed that deforestation and habitat modification could pose a threat for this species, although to date no health assessment has been done. The aim of this study was to generate health baseline data on P. gutturosus. Forty Berthold’s bush anoles (20 males and 20 females) were sampled at the Pacific versant in Costa Rica, where physical examination, skin and cloacal temperatures, and blood samples were obtained from individuals immediately after capture. Animals from the studied population were all healthy (body condition 2.5–3.0/5.0). No lesions or ectoparasites were detected, but hemoparasites were found in nine individuals. Hematological and biochemical values were obtained, and the morphology of leukocytes were found to be similar to other iguanians. A positive correlation was found between the tissue enzymes aspartate aminotransferase (AST) and creatinine kinase (CK) and a negative correlation was found between skin and cloacal temperatures and AST and CK. There were positive correlations between female weight and total protein, calcium, and the calcium and phosphorus ratio. No significant inter-sex differences were found in biochemical values, despite females being larger than males. This is the first health assessment performed on a free-ranging canopy dwelling lizard. These findings provide baseline data that may be useful for future monitoring if the species faces changes in health status due to anthropogenic causes or natural disturbances.

Physiological implications of life at the forest interface of oil palm agriculture: blood profiles of wild Malay civets (Viverra tangalunga)

Agricultural development is a major threat to global biodiversity, and effective conservation actions are crucial. Physiological repercussions of life alongside human-modified landscapes can undermine adaptable species' health and population viability; however, baseline data are lacking for many wildlife species. We assessed the physiological status of a generalist carnivore, the Malay civet (Viverra tangalunga), persisting within an extensively human-modified system in Sabah, Malaysian Borneo. We characterized hematology and serum biochemistry panels from civets sampled across a mosaic landscape comprising tropical forest fragments and oil palm plantations. Intra-population variation in certain blood parameters were explained by expected biological drivers such as sex, age category and sampling season. Furthermore, we determined several erythrocyte measures, immune cell counts and dietary biochemistry markers significantly varied with proximity to oil palm plantation boundaries. These findings were supported by a case study, whereby blood profiles of GPS collared male civets were contrasted based on their exclusive use of forests or use of oil palm plantations. These data provide robust and valuable first insights into this species' physiological status and suggest agricultural landscapes are impacting the persisting population.

Reframing conservation physiology to be more inclusive, integrative, relevant and forward-looking: reflections and a horizon scan

Applying physiological tools, knowledge and concepts to understand conservation problems (i.e. conservation physiology) has become commonplace and confers an ability to understand mechanistic processes, develop predictive models and identify cause-and-effect relationships. Conservation physiology is making contributions to conservation solutions; the number of 'success stories' is growing, but there remain unexplored opportunities for which conservation physiology shows immense promise and has the potential to contribute to major advances in protecting and restoring biodiversity. Here, we consider how conservation physiology has evolved with a focus on reframing the discipline to be more inclusive and integrative. Using a 'horizon scan', we further explore ways in which conservation physiology can be more relevant to pressing conservation issues of today (e.g. addressing the Sustainable Development Goals; delivering science to support the UN Decade on Ecosystem Restoration), as well as more forward-looking to inform emerging issues and policies for tomorrow. Our horizon scan provides evidence that, as the discipline of conservation physiology continues to mature, it provides a wealth of opportunities to promote integration, inclusivity and forward-thinking goals that contribute to achieving conservation gains. To advance environmental management and ecosystem restoration, we need to ensure that the underlying science (such as that generated by conservation physiology) is relevant with accompanying messaging that is straightforward and accessible to end users.

Striving for population-level conservation: integrating physiology across the biological hierarchy

The field of conservation physiology strives to achieve conservation goals by revealing physiological mechanisms that drive population declines in the face of human-induced rapid environmental change (HIREC) and has informed many successful conservation actions. However, many studies still struggle to explicitly link individual physiological measures to impacts across the biological hierarchy (to population and ecosystem levels) and instead rely on a 'black box' of assumptions to scale up results for conservation implications. Here, we highlight some examples of studies that were successful in scaling beyond the individual level, including two case studies of well-researched species, and using other studies we highlight challenges and future opportunities to increase the impact of research by scaling up the biological hierarchy. We first examine studies that use individual physiological measures to scale up to population-level impacts and discuss several emerging fields that have made significant steps toward addressing the gap between individual-based and demographic studies, such as macrophysiology and landscape physiology. Next, we examine how future studies can scale from population or species-level to community- and ecosystem-level impacts and discuss avenues of research that can lead to conservation implications at the ecosystem level, such as abiotic gradients and interspecific interactions. In the process, we review methods that researchers can use to make links across the biological hierarchy, including crossing disciplinary boundaries, collaboration and data sharing, spatial modelling and incorporating multiple markers (e.g. physiological, behavioural or demographic) into their research. We recommend future studies incorporating tools that consider the diversity of 'landscapes' experienced by animals at higher levels of the biological hierarchy, will make more effective contributions to conservation and management decisions.

Cortisol modulates metabolism and energy mobilization in wild-caught pumpkinseed (Lepomis gibbosus)

Acute elevation of cortisol via activation of the hypothalamic-pituitary-interrenal (HPI) axis aids the fish in dealing with a stressor. However, chronic elevation of cortisol has detrimental effects and has been studied extensively in lab settings. However, data pertaining to wild teleosts are lacking. Here, we characterized the metabolic consequences of prolonged cortisol elevation (96 h) in wild-caught pumpkinseed (Lepomis gibbosus). Pumpkinseed were implanted with cocoa butter alone (sham) or containing cortisol (25 mg kg^-1 body weight), and at 24, 48, 72, and 96 h, tissue samples were collected, whole-body ammonia excretion was determined, and whole-organism metabolism was assessed using intermittent flow respirometry. Cortisol-treated pumpkinseed exhibited the highest plasma cortisol concentration at 24 h post-implantation, with levels decreasing over the subsequent time points although remaining higher than in sham-treated fish. Cortisol-treated fish exhibited higher standard and maximal metabolic rates than sham-treated fish, but the effect of cortisol treatment on aerobic scope was negligible. Indices of energy synthesis/mobilization, including blood glucose concentrations, hepatosomatic index, hepatic glycogen concentrations, and ammonia excretion rates, were higher in cortisol-treated fish compared with controls. Our work suggests that although aerobic scope was not diminished by prolonged elevation of cortisol levels, higher metabolic expenditures may be of detriment to the animal's performance in the longer term.

Botanic gardens should lead the way to create a "Garden Earth" in the Anthropocene

The strength and expertise that botanic gardens bring to conservation are based on their detailed knowledge and understanding of the care, management, and biology of a diversity of plant species. This emphasis on the organism has led to many ex-situ and in-situ conservation programs aimed at protecting endangered species, restoring threatened populations, and establishing living plant and seed collections of endangered species. In China, the scale and pace of change in land and resource use, often leading to environmental degradation, has created a strong emphasis on improving environmental conditions. If done properly, being "green" can be a surprisingly complex issue, because it should encompass and exploit the whole of plant diversity and function. Unfortunately, 'green' often includes a small portion of this whole. Earth's rich plant diversity presents considerable opportunity but requires expertise and knowledge for stable and beneficial management. With the dawning of the Anthropocene, we should strive to live on a "Garden Earth", where we design and manage our environments, both built and natural, to create a healthy, beneficial living landscape for people and other organisms. The staff of botanic gardens worldwide and the living collections they maintain embody the best examples of sustainable, beautiful, and beneficial environments that thrive on plant diversity. This expertise should be a fundamental resource for agencies in all sectors responsible for managing and designing "green" infrastructure. Botanic gardens should actively engage and contribute to these opportunities, from large public infrastructure projects to small private conservation efforts. Here, we discuss several ongoing conservation efforts, primarily in China, and attempt to identify areas where botanic gardens could make a significant and meaningful difference.