Migratory Species and Health: A Review of Migration and Wildlife Disease Dynamics, and the Health of Migratory Species, within the Context of One Health

A desire for good health unites us all. Still in a time of COVID-19 and with the looming threat of future pandemics, we are reminded of the fragility of our collective health. Now more than ever, we understand that human health is inexorably linked to the health of the environment in which we live and the species, be they wild or domestic, on which we depend. As we threaten and change our climate, transform natural landscapes, intensify our agriculture
activities, unsustainably exploit resources, and pollute our air, land and water, the pressures on the environment and on migratory species have never been greater. All of these actions in turn drive the emergence of diseases and increase our fragility. I have lived through a time when diseases of wildlife may have been only of scientific interest to some. Now we see the wider and significant consequences of the emergence of both infectious and non-infectious diseases and the growing threat they pose to the very survival of species.
Bringing UNEP into the health Quadripartite to work alongside the World Health
Organization, UN Food and Agriculture Organization and the World Animal Health Organization is a clear sign that, as a society, if we are to tackle global human ill-health we need to pay significant attention to One Health, taking a holistic approach to disease issues at the global level. Yet within One Health the environment and wildlife health are too often the ‘poor relation.’ There remains too little understanding of disease dynamics and scant consideration of wildlife health when making decisions on food production, trade, land planning, energy production and infrastructure development. Due to the now obvious interconnectivity of health, we know that what is bad for wildlife health, is ultimately bad for us.
Too often we overlook the value of wildlife health, only opening our eyes when we feel the negative consequence for human ill-health. For example, when we are confronted with the appalling sights of acute outbreaks of diseases like highly pathogenic avian influenza, or when wildlife diseases spill into livestock or zoonotic infections affect people and present pandemic risks. There is a need to turn the adage of ‘no prizes in prevention’ into applauded actions to maintain the integrity and resilience of ecosystems to stop disease emergence at its source. Developing cost-effective ways to prevent disease emergence that also benefit ecosystems is surely a key challenge for the future.
This Report, authored and reviewed by a world leading team of wildlife health specialists, led by the University of Edinburgh, contributes to the growing body of work which highlights the needs for interdisciplinary action to protect the health of us all. Instead of viewing issues through the single anthropocentric lens of human health, it takes the perspective of the wider environment and of the species within, helping to rebalance and improve our thinking about
One Health.
The Report is a seminal contribution to the work of the Convention on Migratory Species (CMS) on the issue of wildlife health and will guide the work of the CMS Working Group on Migratory Species and Health. It adds to the CMS work on One Health issues such as the poisoning of species, and highly pathogenic avian influenza, which has helped guide Parties and other stakeholders dealing with the negative health consequences of human activities.
The Report examines our current understanding of the determinants of health and considers the gains to be made from taking One Health approaches. With a frequent perception of migratory species as vectors of disease it reviews the complexities of their disease dynamics and considers both the benefits and dis-benefits that migration brings for health in all sectors. Importantly, the report provides the findings from a global expert consultation of key health threats for CMS-listed species. Despite the diversity of species considered, from insects to elephants, and their diverse health threats, there is remarkable similarity in the
underlying drivers of their health threats, namely the human induced pressures outlined above.
The key recommendations1 outline the frameworks required to deliver One Health, and how to reduce risks at wildlife interfaces, tackle non-infectious diseases, improve disease prevention and preparedness, fill knowledge gaps, and improve wildlife health reporting and information sharing. These actions will not only improve the conservation status of migratory species, but they will also reduce the health risks to people and livestock.
In a climate changing world with an interlinked global biodiversity crisis where the consequences of the current Covid pandemic still playing out, we need no more warnings, we now know now what we have to do to act for the health of us all.