Natural and Historical Overview of the Animal Wildlife-Livestock Interface

Abstract

The interfaces among different compartments have been spaces of transition and contact where pathogens have adapted to new hosts. The domestication and establishment of local settlements modelled multiple wildlife–livestock–human interfaces, characterized by the maintenance of “crowd diseases” (both by humans and/or by animals) and the continuous presence of a domestic pathogen reservoir. Through the course of human history, our impact on the natural environment has increasingly magnified, including our ability to alter, shape, and reshape nature at different rates, often varying by epochs, civilizations, and regions. Human expansion, technical development, trade, population growth, and growing interdependence of the global economy have both increased livestock spatial ranges and opportunities for animal pathogens to cross geographic boundaries. Correspondingly, there is a greater risk of disease re-emergence and potential spillback into wildlife populations that may act as disease reservoirs, which has determined the characteristics of wildlife–livestock interfaces and subsequent opportunities for pathogen transfer that exist today. The wildlife–livestock–human interface has also intensified as a result of human encroachment into historically wilderness areas, especially in tropical ecosystems. Thus, the wildlife–livestock interface has advanced to become more interconnected than ever as humans and animals (domestic and wild) increasingly share a common global infectious disease ecology (i.e., the wildlife–livestock interface is becoming global). However, the severity of disease related human–wildlife conflicts has a complex nature. While wildlife is becoming less abundant and more fragmented, wildlife–livestock interfaces have become more frequent and interconnected. For example, although there are catastrophic wild species extinctions in certain regions (e.g., tropical forests), we also observe the recovery or expansion of some wildlife populations over expansive areas that are associated with increased sanitary risks at the human–livestock interface (e.g., ungulates in temperate regions of the Northern hemisphere). Therefore, mitigating disease risk at wildlife–livestock–human interfaces must be a crucial component of modern wildlife management and it is essential to understand local, regional, and international social, economic, and cultural systems to better focus strategic disease control programs. Integral population and disease monitoring are also necessary to improve knowledge of the role of wildlife and the mode of transmission and emergence of new infections. Climate and associated anthropogenic and environmental change are impacting the distribution, abundance, behavior, and population dynamics of pathogens and hosts, threatening human health, and livelihoods. The current context urgently requires a better understanding of global warming impacts on the wildlife–livestock–human interface, particularly in complex host/pathogen/vector systems. Transdisciplinary integrative approaches that enable countries and international organizations to better target shared disease control programs and move toward disease eradication, which includes strategic research in collaboration with the medical sector, will be required to ensure decisions are scientifically informed for current challenges in the interest of humanity.