The role of conservation physiology in mitigating social-ecological traps in wildlife-provisioning tourism: a case study of feeding stingrays in the Cayman Islands

In feeding marine wildlife, tourists can impact animals in ways that are not immediately apparent (i.e. morbidity vs. mortality/reproductive failure). Inventorying the health status of wildlife with physiological indicators can provide crucial information on the immediate status of organisms and long-term consequences. However, because tourists are attempting to maximize their own satisfaction, encouraging the willingness to accept management regulations also requires careful consideration of the human dimensions of the system. Without such socio-ecological measures, the wildlife-tourism system may fall into a trap—a lose–lose situation where the pressure imposed by the social system (tourist expectations) has costs for the ecological system (maladaptive behaviours, health), which in turn feed back into the social system (shift in tourist typography, loss of revenue, decreased satisfaction), resulting in the demise of both systems (exhaustion). Effective selection and communication of physiological metrics of wildlife health is key to minimizing problem-causing and problem-enhancing feedbacks in social-ecological systems. This guiding principle is highlighted in the case study presented here on the socio-ecological research and management success of feeding southern stingrays (Hypanus americanus) as a marine tourism attraction at Grand Cayman, Cayman Islands.

Weathering the impacts of climate change

Ectothermic organisms experience their local environments in ways that humans can have difficulty conceptualizing. Physics-based (ecomechanical) approaches, for example heat budget models, can lend insights into how an organism’s very local environmental conditions (microclimate) can drive niche-level conditions such as body temperature; these in turn drive physiological processes. Quantitative methods also allow insights into the temporal and spatial scales that may ultimately determine responses to larger-scale environmental change. For example, for small, sessile organisms, microhabitats such as crevices in rocks may provide microrefugia that allow survival during heat waves. As a result, larger-scale recovery following heat waves (rescue effects) may ultimately be influenced by much smaller-scale processes. Ecomechanics techniques also facilitate the use of interventions such as shading that can maintain environmental conditions within physiological tolerance levels.

Optimism and opportunities for conservation physiology in the Anthropocene

We discuss 12 themes that emerged from the set of case studies comprising the text, namely: (1) mechanisms matter for conservation; (2) physiology is just one source of knowledge; (3) physiology and behaviour are intertwined; (4) new tools and technologies should be embraced; (5) physiology can be valuable in captive settings; (6) conservation physiology extends across scales; (7) physiology can be incorporated into long-term monitoring programmes; (8) conservation physiology is applicable to invertebrates; (9) non-imperilled species deserve attention; (10) successful application is increased by co-production; (11) sharing success stories is important; and (12) findings should be communicated across a variety of platforms. We end the chapter with a discussion of some of the challenges currently being faced in the discipline, and with a message of optimism for the future.

On conducting management-relevant mechanistic science for upriver migrating adult Pacific salmon

Pacific salmon undertake iconic homeward migrations where they move from ocean feeding grounds to coastal rivers where they return to natal spawning sites. However, this migration is physiologically challenging as fish have to navigate past predators, nets, hooks, and dams while dealing with variable flows, warm water temperatures, and pathogens. These challenges often interact in synergistic ways that can sometimes lead to migration failure. The conservation physiology toolbox has led to new understanding of how salmon deal with different challenges with a goal of generating management-relevant science. Given the sensitivity of Pacific salmon to warm temperatures, much research has focused on identifying thermal thresholds. In addition, physiology has informed the development of methods for recovering fish that are exhausted from fisheries interactions and for enhancing passage success at fishways. These successes have arisen in part due to the extent to which we partnered with fisheries managers and other stakeholders to ensure that we were conducting relevant research.

Using applied physiology to better manage and conserve the white rhinoceros (Ceratotherium simum)

The white rhinoceros (Ceratotherium simum), one of five remaining rhinoceros species, is particularly sensitive to etorphine, the opioid drug used for chemical capture. As a result, capture often results in morbidity and mortality. With the recent, unprecedented rise in rhino poaching, fuelled by a growing demand for rhino horn, intensive management procedures, including chemical capture, are key to the conservation and management of this large iconic species. The use of sophisticated physiological monitoring techniques in rhinoceros undergoing capture and other management procedures (e.g. translocation) and experimental trials of different pharmacological interventions have provided insights into the causes and consequences of capture-related pathophysiology. This chapter explores some of the approaches used to investigate physiological responses of the white rhinoceros, and how the results from experimental trials are helping us move towards safer methods of chemical capture and transport.

Integrating physiological and ecological data to increase the effectiveness of bee protection and conservation

Due to growing anthropogenic pressures, substantial losses of honeybee colonies (Apis mellifera) have been reported around the world, and the species richness and abundance of most groups of wild bees have declined in recent decades across Europe and North America. Assessing the possible impacts of ongoing and future environmental changes and developing mitigative policies are therefore of top priority to conservationists. For that purpose, there is an urgent need to identify new metrics that can be used to capture the state of health of bees and therefore improve their population monitoring. We show that a combination of landscape ecology and physiological metrics of honeybee health status is a highly valuable approach to measure the efficiency of habitat-restoration and enhancement schemes. We then argue for the development of this approach to better assist conservation strategies of wild bees.

Applications of minimally invasive immune response and glucocorticoid biomarkers of physiological stress responses in rescued wild koalas (Phascolarctos cinereus)

Australasian biodiversity is facing immense challenges with losses of prime habitats and food sources through increased anthropogenic factors such as climate change, bushfires, and habitat modification. Wildlife species are requiring greater conservation intervention supported through numerous wildlife rescue and rehabilitation programmes in this region. It is important to record the physiological stress responses of rescued wildlife and currently available conservation physiology tools can certainly aid the conservation management and rehabilitation of rescued wildlife. In this chapter, we showcase the applications of minimally invasive stress hormone and immune response (haematological blood cell profiling) biomarkers using case studies of rescued koalas (Phascolarctos cinereus) to quantify their physiological stress responses to environmental trauma and disease conditions, and clinical intervention. Applications of these physiological biomarkers can advance our understanding of how wildlife respond towards and cope with environmental challenges and support conservation goals of rescue centres to strengthen wildlife rehabilitation and release back to the wild once the proximate stressors have been eliminated.

Physiology provides a window into how the multi-stressor environment contributes to amphibian declines

The amphibian disease chytridiomycosis, caused by two fungal pathogens in the genus Batrachochytrium, has caused the greatest vertebrate biodiversity loss due to disease in recorded history. Both the pathogens and their amphibian hosts are impacted by biotic and abiotic conditions that are rapidly changing due to anthropogenic causes, challenging our understanding of how the host–pathogen relationship will shift in the future. By examining this problem through a physiological lens, we can elucidate the mechanisms driving increased susceptibility to disease. This chapter first examines the physiological tools that can be used by amphibian biologists to measure aspects of immune function, stress physiology, and energy expenditure, and the main environmental drivers of these physiological shifts. Then, we explore case studies that have linked environmental change, immune function, and shifts in disease susceptibility to inform amphibian conservation and management.

Using physiological tools to unlock barriers to fish passage in freshwater ecosystems

Globally, freshwater fish numbers have declined substantially in part due to anthropogenic structures (e.g. dams) that impede fish movements. The environmental and societal benefits of balancing environmental health with human resource requirements have meant that there is increasingly a concerted effort to remove or remediate barriers to fish passage. However, this is technically, financially, and biologically challenging. Experimental approaches provide a controlled, iterative, integrative, and cost-effective approach to assess the physical, physiological, and behavioural limitations of fish that can be used to provide evidence-backed information to support or develop remediation practices. This chapter explores some of the physiological tools used to measure fish performance in modified environments, and how empirical studies are informing current issues in the management of freshwater fish passage.

Transcriptome profiling in conservation physiology and ecotoxicology: mechanistic insights into organism–environment interactions to both test and generate hypotheses

A key challenge in conservation biology is to identify natural populations with compromised health and identify causative agents. However, wildlife are exposed to a complex matrix of natural and anthropogenic stressors such that identifying particular agents of distress is difficult. Yet, establishing cause and effect between human-induced environmental changes and adverse health is necessary to guide conservation planning. Transcriptome profiling, with thoughtful experimental design and appropriate metadata, is useful for establishing cause and effect between exposures to environmental stressors and adverse health outcomes. Here we describe transcriptome profiling and associated paradigms that are useful for wildlife health assessment and conservation planning, with particular emphasis on pollution. We emphasize that these tools are important for testing hypotheses about causative agents of distress, but also for generating new hypotheses about causes and consequences. We outline two case studies that highlight attributes of transcriptomics tools and approaches that add value for conservation practitioners.